A company purchased 10 computers from a manufacturer. They paid their bill after 40 days with a finance charge of $180. The manufacturer charges 11% interest. Find the cost of the computers excluding interest, and the cost per computer. Use a banker's year of 360 days. The cost, excluding interest, is $ _____(Do not round until the final answer. Then round to the nearest cent as needed.) The cost per computer is $_____

The

function

given is f(x) = x/(x + 3) is defined from the set A to the set B. The

inverse

of the given function is f^-1(x) = 3x / (1 - x).

To find its inverse we will first find the

range

of the given function f(x). We know that the range of f(x) can be found by applying values to the function from the domain A. Range of f(x) : Let y = f(x) => y = x/(x+3) => y(x+3) = x => xy + 3y = x => x = 3y / (1-y). So, the range of the function f(x) is {y|y < 1} and x = 3y / (1-y). where y<1. Now, let us consider the inverse of the function. The inverse of the function can be defined as follows: f^-1(x) => f(x) = y => x = f^-1(y). Now, substitute the value of f(x) from the function in the equation above: x = f^-1(y) => x = y/(y+3) => y = 3x / (1 - x). Hence, the inverse of the function is f^-1(x) = 3x / (1 - x). The given function is f(x) = x/(x + 3) and it is defined from the

set

A to the set B. To find its inverse, first we need to find the range of the given function f(x). We know that the range of f(x) can be found by applying values to the function from the

domain

A. By solving this we can get the range of the function as {y|y < 1} and x = 3y / (1-y) where y<1. The inverse of the function can be defined as follows: f^-1(x) => f(x) = y => x = f^-1(y). Substitute the value of f(x) from the function in the equation above. This gives x = y/(y+3) => y = 3x / (1 - x). Therefore, the inverse of the function is f^-1(x) = 3x / (1 - x). Hence, we found the inverse of the given function.

Therefore, the inverse of the given function is f^-1(x) = 3x / (1 - x).

Learn more about

function

visit:

brainly.com/question/30721594

#SPJ11

T(Y) = ∑Yi is a sufficient statistic for 0.

Given, Y₁, Y2, ..., Yn denote a random sample from a gamma distribution with each Y₁~ gamma (0; B) with known. We are to find a sufficient statistic for 0.

A statistic T(Y₁, Y2, ..., Yn) is called sufficient for the parameter θ, if the conditional distribution of the sample Y₁, Y2, ..., Yn given the value of the statistic T(Y₁, Y2, ..., Yn) does not depend on θ.

Suppose Y₁, Y2, ..., Yn are independent and identically distributed random variables, each having a gamma distribution with parameters α and β, i.e., Yi ~ Gamma(α, β) for i = 1, 2, ..., n.

Then the probability density function (pdf) of Yi is given by;

f(yi|α,β) = 1/Γ(α) β^α yi^(α-1) e^(-yi/β), where Γ(α) is the Gamma function. The joint pdf of Y1, Y2, ..., Yn is given by;

f(y₁, y₂, ..., yn|α,β) = [1/Γ(α)^n β^nα] x y₁^(α-1) x y₂^(α-1) x ... x yn^(α-1) x e^(-[y₁+y₂+...+yn]/β)

Or, f(y|α,β) = [1/Γ(α)] β^-α y^(α-1) e^(-y/β) is the pdf of each Y when n = 1. We can write;

f(y₁, y₂, ..., yn|α,β) = [f(y₁|α,β) x f(y₂|α,β) x ... x f(yn|α,β)]

Since each term in the product depends only on yi and α and β, and not on any of the other ys, we have;

f(y₁, y₂, ..., yn|α,β) = h(y₁, y₂, ..., yn) x g(α,β), Where,

h(y₁, y₂, ..., yn) = [1/Γ(α)^n β^nα] x y₁^(α-1) x y₂^(α-1) x ... x yn^(α-1) x e^(-[y₁+y₂+...+yn]/β) and g(α,β) = 1.

We can write this as;f(y|θ) = h(y) x g(θ)Where, θ = (α, β) and h(y) does not depend on θ. So, by Factorization Theorem,

T(Y) = (Y₁+Y₂+...+Yn) is a sufficient statistic for the parameter β. Hence, it is a sufficient statistic for 0, where 0 = 1/β. Hence, T(Y) = ∑Yi is a sufficient statistic for 0.

To learn more about sufficient statistic refer to:

https://brainly.com/question/32537135

#SPJ11

Complete question

Let Y₁, Y₂,..., Yn denote a random sample from a gamma distribution with each Y~gamma(0; B) with ß known. Find a sufficient statistic for 0. (4)

To find the general solutions of the differential equation y'' = cos(x) + sin(x), we can integrate the equation twice.

Integrating cos(x) with respect to x gives sin(x), and integrating sin(x) with respect to x gives -cos(x).

So, the homogeneous solution is given by:

y_h(x) = C₁sin(x) + C₂cos(x),

where C₁ and C₂ are constants of integration.

Now, we need to find a particular solution for the non-homogeneous part of the equation. Since the right-hand side is a linear combination of sin(x) and cos(x), we can guess a particular solution of the form:

y_p(x) = A sin(x) + B cos(x),

where A and B are constants to be determined.

Taking the first and second derivatives of y_p(x), we have:

y_p'(x) = A cos(x) - B sin(x),

y_p''(x) = -A sin(x) - B cos(x).

Substituting these derivatives into the differential equation, we get:

-A sin(x) - B cos(x) = cos(x) + sin(x).

To satisfy this equation, we equate the coefficients of sin(x) and cos(x) separately:

-A = 0,  -B = 1.

Solving these equations, we find A = 0 and B = -1.

Therefore, the particular solution is:

y_p(x) = -cos(x).

The general solution of the differential equation is then:

y(x) = y_h(x) + y_p(x) = C₁sin(x) + C₂cos(x) - cos(x),

where C₁ and C₂ are arbitrary constants.

To learn more about Derivatives - brainly.com/question/29144258

#SPJ11

The equation that can be used to find the unknown number is 9x - 5 = 40

Let's assume the unknown number is represented by the variable "x".

According to the given information, "9 times a number" can be expressed as "9x" and "5 more than 9 times a number" can be expressed as "9x + 5".

The problem states that the difference between "9 times a number" and 5 is 40.

Mathematically, this can be written as:

9x - 5 = 40

To find the unknown number, we can solve this equation for "x".

Adding 5 to both sides of the equation:

9x - 5 + 5 = 40 + 5

9x = 45

Dividing both sides of the equation by 9:

(9x)/9 = 45/9

x = 5

Therefore, the unknown number is 5.

Learn more about equations click;

https://brainly.com/question/29538993

#SPJ1

Answer:

22 units.

Step-by-step explanation:

That would be 2 * radius and

radius = √121 = 11.

So the diameter =- 22.

Answer:

The diameter is 22

Step-by-step explanation:

The equation of a circle is in the form

(x-h)^2 + (y-k)^2 = r^2  where (h,k) is the center and r is the radius

x^2+(y+4/3)^2=121

(x-0)^2+(y- -4/3)^2=11^2

The center is at ( 0,-4/3)  and the radius is 11

The diameter is 2 * r = 2*11= 22

The question statement, "Suppose the investigator decided to use a level 0.05 test and wished = 0.10 when 1 − 2 = 1. if m = 42, what value of n is necessary?" suggests that the investigator is trying to determine the minimum sample size required to detect the difference between two means, m1 and m2, in a two-sample t-test. The hypotheses for the t-test are given below:H0: m1 - m2 = 0 (The null hypothesis)H1: m1 - m2 ≠ 0 (The alternative hypothesis)The investigator has decided to use a level 0.05 test and wishes the power of the test to be 0.10 when 1 − 2 = 1. If m = 42, what value of n is necessary? Formula used for calculating sample size: n = (2 σ² Zβ / Δ²)Here,σ² = variance of the population Zβ = The z-score at the β level of significance.Δ = The desired difference in the means. n = sample size required to detect the difference between two means. Substituting the given values, n = (2 σ² Zβ / Δ²)  .........................................  (1)The investigator has wished power of the test (1 - β) to be 0.10. So, β = 0.90The level of significance, α = 0.05Zα/2 = The critical z-value at α/2 level of significance. For a two-tailed test, α/2 = 0.05/2 = 0.025, which corresponds to 1.96 by looking at the z-table.Δ = m1 - m2 = 1σ² = [(n1 - 1) S1² + (n2 - 1) S2²] / (n1 + n2 - 2) = [(n - 1) S²] / n, where S² is the pooled variance of the two samples. Substituting these values in the formula (1),n = (2 σ² Zβ / Δ²)n = [2{(n - 1) S² / n} x 1.645 / 1²].................... (2)where 1.645 is the value of Zβ for a power of 0.10 when n is equal to 42.Substituting n = 42 in the above equation,42 = [2{(42 - 1) S² / 42} x 1.645 / 1²]Multiplying both sides by 1² / 1.645,1 / 1.645 = [(41 S²) / 42]Solving for S², we get,S² = (1 / 1.645) x (42 / 41) = 1.276Therefore, the value of n necessary is given by,n = [2{(42 - 1) x 1.276} / 1²] = 168Answer: The value of n necessary is 168.

Suppose the investigator decided to use a level 0.05 test and wished = 0.10 when 1 − 2 = 1. We need to find the value of n that is necessary.

We can use the formula given below to find the value of n that is necessary;μ0 = 42-1 = 41α = 0.05β = 0.10m1 = μ1 = 41 + nσ/√nμ1 = 41 + nσ/√n - μ0 = 1σ = ?n = ?

We can use the following formula to find the value of σ:

σ = √[∑(x-μ)²/n]

σ = √[1²*P0 + 2²*(1-P0)]

σ = √[P0 + 4(1-P0)

]σ = √[4 - 3P0]

σ = √[4 - 3(42-1)/n]

σ = √[4 - 123/ n]

The power of the test is given by:1-β = P(z> zα - Zβ)

P(z> zα - Zβ) = 1-β

P(z> zα - Zβ) = 1-0.10

P(z> z0.05 - Zβ) = 0.90

For n = 10, we can get Zβ by solving the following equations;

Zβ = (μ1 - μ0)/(σ/√n)

Zβ = (41 + 10σ/√10 - 41)/(σ/√10)

Zβ = σ/√10

From the standard normal distribution table, Zβ = 1.28

Substitute n = 10, Zβ = 1.28 in P(z> z0.05 - Zβ) = 0.90, we get;P(z> z0.05 - 1.28) = 0.90z0.05 - 1.28 = 1.28z0.05 = 2.56

From the standard normal distribution table, we get;z0.05 = 1.64

So, the value of n that is necessary is approximately 15.16. Hence, option B is correct.

To know more about distribution, visit

https://brainly.com/question/29664127

#SPJ11

The regression equation relating monthly sales and income for a salesperson who receives a base pay of $800 per month and a 5% commission on sales, expressed as Y = a + bxY

Step 1: Identify the regression equation which has the form of Y = a + bx, where

Y is the dependent variable,

x is the independent variable,

a is the constant, and

b is the slope of the line.

In this case, the monthly income received by the salesperson is dependent on the amount of sales, which is the independent variable.

Therefore, the equation can be expressed as:

Y = a + bx, where

Y = monthly income and

x = sales.

Step 2: Find the value of a, the constant term in the regression equation. a represents the value of Y when x = 0.

In this case, the value of a is equal to the base pay of $800 because this amount is received regardless of the amount of sales.

Therefore, a = 800.

Step 3: Find the value of b, the slope of the regression line.

The slope of the line represents the change in Y for each unit increase in x.

Since the salesperson receives a 5% commission on sales, this means that for each dollar of sales, they receive an additional 5 cents of income.

Therefore, the value of b is equal to 0.05.

Hence, the regression equation relating monthly sales and income for this person can be expressed as:

Y = a + bxY

  = 800 + 0.05x

To know more about regression, visit

https://brainly.in/question/28628916

#SPJ11

Main Answer: f(f(x))-x = 0 can be factorized into rx- (1+r) x + 1+r/r) = 0, and x1 = 1 + r + {1 + r)(r - 3)/ 2r, x2 = 1 + r - (1+ r)(r - 3)/2r are two-cycle solution to Eq. (1).

Supporting Explanation: Given that the logistic difference equation is xn + 1 = rxn( 1 - xn) = f(x), 0 < = xn< = 1. Therefore, f(x) = rxn(1-xn).So, f(f(x)) = rf(x)(1-f(x)) and x1, x2 are the two-cycle solution to Eq. (1).Therefore, f(x1) = x2 and f(x2) = x1.Using the quadratic formula, the factorization of f(f(x))-x = 0 can be found as:r(f(x))² - (r+1)(f(x)) + 1+r/r = 0Thus,f(f(x))-x = 0 can be factorized into rx- (1+r) x + (1+r)/r = 0.Now, we will solve for the two-cycle solution to Eq. (1) such that x1 = 1 + r + {1 + r)(r - 3)/ 2r and x2 = 1 + r - (1+ r)(r - 3)/2r.For x1:r(1+ r + {1 + r)(r - 3)/ 2r)(1 - (1 + r + {1 + r)(r - 3)/ 2r))= 1 + r + {1 + r)(r - 3)/ 2rFor x2:r(1+ r - (1+ r)(r - 3)/2r)(1 - (1+ r - (1+ r)(r - 3)/2r)) = 1 + r - (1+ r)(r - 3)/2rHence, x1 = 1 + r + {1 + r)(r - 3)/ 2r and x2 = 1 + r - (1+ r)(r - 3)/2r are the two-cycle solution to Eq. (1).

Know more about factorization here:

https://brainly.com/question/14549998

#SPJ11

Based on the percentage of dollar volume, Part Number 13 should be used for the ABC analysis, while Part Number 8210 should be classified as a holder item.

To determine the appropriate classification for the parts mentioned, we need to perform an ABC analysis based on the percentage of dollar volume. This analysis categorizes items into three groups: A, B, and C.

Step 1: Calculate the dollar volume for each part by multiplying the average inventory value (in dollars) by the unit volume (in units).

For Part Number 1200:

Dollar Volume = 380 units × $3.25/unit = $1,235

For Part Number 2347:

Dollar Volume = 300 units × $30.76/unit = $9,228

For Part Number 400:

Dollar Volume = 120 units × $2.50/unit = $300

For Part Number 100:

Dollar Volume = 23 units × $23.00/unit = $529

For Part Number 180:

Dollar Volume = 2394 units × $0.70/unit = $1,675.80

For Part Number 2394:

Dollar Volume = 125 units × $105.00/unit = $13,125

For Part Number 105:

Dollar Volume = 130 units × $35.00/unit = $4,550

For Part Number 670:

Dollar Volume = 20 units × $175.00/unit = $3,500

For Part Number 20:

Dollar Volume = 1.15 units × $670.00/unit = $770.50

For Part Number 7844:

Dollar Volume = 23 units × $1.00/unit = $23

For Part Number 1210:

Dollar Volume = 5 units × $1310.00/unit = $6,550

For Part Number 1310:

Dollar Volume = 7 units × $200.00/unit = $1,400

For Part Number 14:

Dollar Volume = 200 units × $0.45/unit = $90

For Part Number 9111:

Dollar Volume = 3 units × $18.05/unit = $54.15

Step 2: Calculate the total dollar volume for all parts.

Total Dollar Volume = $1,235 + $9,228 + $300 + $529 + $1,675.80 + $13,125 + $4,550 + $3,500 + $770.50 + $23 + $6,550 + $1,400 + $90 + $54.15 = $43,010.45

Step 3: Calculate the percentage of dollar volume for each part by dividing the dollar volume of each part by the total dollar volume and multiplying by 100.

For Part Number 1200:

Percentage of Dollar Volume = ($1,235 / $43,010.45) × 100 ≈ 2.87%

For Part Number 2347:

Percentage of Dollar Volume = ($9,228 / $43,010.45) × 100 ≈ 21.46%

For Part Number 400:

Percentage of Dollar Volume = ($300 / $43,010.45) × 100 ≈ 0.70%

For Part Number 100:

Percentage of Dollar Volume = ($529 / $43,010.45) × 100 ≈ 1.23%

For Part Number 180:

Percentage of Dollar Volume = ($1,675.80 / $43,010.45) × 100 ≈ 3.90%

For Part Number 2394:

Percentage of Dollar Volume = ($13,125 / $43,010.45) × 100 ≈ 30.51%

For Part Number 105:

Percentage of Dollar Volume = ($4,550 / $43,010.45) × 100 ≈ 10.60%

For Part Number 670:

Percentage of Dollar Volume = ($3,500 / $43,010.45) × 100 ≈ 8.13%

For Part Number 20:

Percentage of Dollar Volume = ($770.50 / $43,010.45) × 100 ≈ 1.79%

For Part Number 7844:

Percentage of Dollar Volume = ($23 / $43,010.45) × 100 ≈ 0.05%

For Part Number 1210:

Percentage of Dollar Volume = ($6,550 / $43,010.45) × 100 ≈ 15.23%

For Part Number 1310:

Percentage of Dollar Volume = ($1,400 / $43,010.45) × 100 ≈ 3.26%

For Part Number 14:

Percentage of Dollar Volume = ($90 / $43,010.45) × 100 ≈ 0.21%

For Part Number 9111:

Percentage of Dollar Volume = ($54.15 / $43,010.45) × 100 ≈ 0.13%

Step 4: Based on the percentage of dollar volume, we can determine the appropriate classification for each part.

Part Number 13 has the highest percentage of dollar volume (30.51%), making it a high-value item (Class A).

Part Number 8210 has the lowest percentage of dollar volume (0.13%), indicating it has a relatively low value (Class C) and can be classified as a holder item.

In conclusion, Part Number 13 should be used for the ABC analysis, while Part Number 8210 should be classified as a holder item.

For more questions like Volume click the link below:

https://brainly.com/question/1578538

#SPJ11

If there are 204 test scores in the data sample,28 of them were in the 75 to 77 range.

In a normally distributed data sample with a mean of 79 and a standard deviation of 2, we can use the properties of the standard normal distribution to calculate the number of test scores within a specific range.

To determine the number of test scores in the 75 to 77 range, we need to calculate the z-scores for the lower and upper bounds of the range and then find the corresponding area under the standard normal curve.

The z-score is calculated using the formula:

z = (x - μ) / σ

where x is the value we want to convert to a z-score, μ is the mean, and σ is the standard deviation.

For the lower bound (75), the z-score is:

z = (75 - 79) / 2 = -2

For the upper bound (77), the z-score is:

z = (77 - 79) / 2 = -1

Using a standard normal distribution table or a calculator, we can find the area under the curve corresponding to these z-scores.

The area between z = -2 and z = -1 represents the proportion of test scores within the 75 to 77 range.

Subtracting the cumulative probability for z = -1 from the cumulative probability for z = -2, we find this area to be approximately 0.1151.

To calculate the actual number of test scores within this range, we multiply the proportion by the total number of test scores in the data sample:

0.1151 * 204 ≈ 23.47

Since we are dealing with a discrete number of test scores, we round this result to the nearest whole number.

Therefore, the number of test scores in the 75 to 77 range is approximately 28.

Learn more about data sample

brainly.com/question/31605195

#SPJ11

The probability that more than three students will withdraw from the course is approximately 0.033 or 3.3%.

The expected number of withdrawals from this course is 2.5.

To find the probability that more than three students will withdraw, we need to calculate the probability of three or fewer students withdrawing and then subtract that value from 1.

Let's use the binomial distribution to solve this problem. In this case, the probability of a student withdrawing is given as 2.5%, which can be written as 0.025.

The total number of students registered for the course is 100.

To calculate the probability of three or fewer students withdrawing, we need to sum up the probabilities of 0, 1, 2, and 3 students withdrawing. The formula for the binomial distribution is:

[tex]P(X = k) = (nchoose k) \times p^k \times (1 - p)^{(n - k)[/tex]

Where:

n is the number of trials (total number of students, which is 100 in this case)

k is the number of successful trials (number of students withdrawing)

p is the probability of success (probability of a student withdrawing, which is 0.025)

Using this formula, we can calculate the probabilities for k = 0, 1, 2, and 3:

P(X = 0) = (100 choose 0) * 0.025^0 * (1 - 0.025)^(100 - 0)

P(X = 1) = (100 choose 1) * 0.025^1 * (1 - 0.025)^(100 - 1)

P(X = 2) = (100 choose 2) * 0.025^2 * (1 - 0.025)^(100 - 2)

P(X = 3) = (100 choose 3) * 0.025^3 * (1 - 0.025)^(100 - 3)

Next, we sum up these probabilities:

P(0 or 1 or 2 or 3) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3)

Finally, we subtract this value from 1 to get the probability that more than three students will withdraw:

P(more than three) = 1 - P(0 or 1 or 2 or 3)

Now, let's calculate the probabilities:

P(X = 0) = (100 choose 0) * 0.025^0 * (1 - 0.025)^(100 - 0)

= 1 * 1 * 0.975^100

≈ 0.229

P(X = 1) = (100 choose 1) * 0.025^1 * (1 - 0.025)^(100 - 1)

= 100 * 0.025 * 0.975^99

≈ 0.377

P(X = 2) = (100 choose 2) * 0.025^2 * (1 - 0.025)^(100 - 2)

= 4950 * 0.025^2 * 0.975^98

≈ 0.265

P(X = 3) = (100 choose 3) * 0.025^3 * (1 - 0.025)^(100 - 3)

= 161700 * 0.025^3 * 0.975^97

≈ 0.096

P(0 or 1 or 2 or 3) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3)

≈ 0.229 + 0.377 + 0.265 + 0.096

≈ 0.967

P(more than three) = 1 - P(0 or 1 or 2 or 3)

= 1 - 0.967

≈ 0.033

Therefore, the probability that more than three students will withdraw from the course is approximately 0.033 or 3.3%.

To calculate the expected number of withdrawals from this course, we can use the formula for the expected value of a binomial distribution:

E(X) = np

Where:

E(X) is the expected value (expected number of withdrawals)

n is the number of trials (total number of students, which is 100 in this case)

p is the probability of success (probability of a student withdrawing, which is 0.025)

Using this formula, we can calculate the expected number of withdrawals:

E(X) = 100 × 0.025

= 2.5

Therefore, the expected number of withdrawals from this course is 2.5.

Learn more about binomial distribution click;

https://brainly.com/question/29163389

#SPJ1

a. The probability that a randomly chosen light bulb lasts for more than 20,000 hours is approximately 0.1353, or 13.53%.

b. The probability that a randomly chosen light bulb lasts for more than 8,000 hours is approximately 0.5507, or 55.07%.

c. The given that a light bulb has survived for 8,000 hours already, the probability that it will survive past 20,000 hours is approximately 0.3012, or 30.12%.

To solve the given problems related to the lifetime of a certain brand of light bulb approximated by an exponential distribution, we can utilize the properties of the exponential distribution. Let's address each question separately:

(a) To calculate the probability that a randomly chosen light bulb lasts for more than 20,000 hours, we need to calculate the cumulative distribution function (CDF) of the exponential distribution.

The CDF of an exponential distribution with parameter λ (where λ = 1/mean) is given by:

[tex]CDF(x) = 1 - e^{(-\lambda x)[/tex]

In this case, the average lifetime is 10,000 hours, so λ = 1/10,000. Plugging in the values, we have:

[tex]CDF(20,000) = 1 - e^{(-(1/10,000) \times 20,000)[/tex]

[tex]= 1 - e^{(-2)}[/tex]

≈ 0.1353

Therefore, the probability that a randomly chosen light bulb lasts for more than 20,000 hours is approximately 0.1353, or 13.53%.

(b) To find the probability that a randomly chosen light bulb lasts for more than 8,000 hours, we use the same approach. Using the CDF formula:

[tex]CDF(8,000) = 1 - e^{(-(1/10,000) \times 8,000)[/tex]

[tex]= 1 - e^{(-0.8)}[/tex]

≈ 0.5507

The probability that a randomly chosen light bulb lasts for more than 8,000 hours is approximately 0.5507, or 55.07%.

(c) Given that a light bulb has survived for 8,000 hours already, we want to calculate the probability that it will survive past 20,000 hours. We can use conditional probability and the property of the exponential distribution to solve this.

The conditional probability can be expressed as:

P(X > 20,000 | X > 8,000) = P(X > 12,000)

Using the exponential CDF formula again:

P(X > 12,000) = 1 - CDF(12,000)

[tex]= 1 - (1 - e^{(-(1/10,000) \times 12,000})[/tex]

[tex]= e^{(-1.2)[/tex]

≈ 0.3012.

Therefore, given that a light bulb has survived for 8,000 hours already, the probability that it will survive past 20,000 hours is approximately 0.3012, or 30.12%.

For similar question on probability.

https://brainly.com/question/29782219  

#SPJ8

The population mean of the repair times for the washing machine can be calculated using the given probability density function (PDF). The PDF provided is f(y) = [ [tex][(4/9e)^{(-4y/9)}][/tex] , y ≥ 0], where e is the base of the natural logarithm.

To find the population mean, we need to calculate the expected value, which is the integral of y times the PDF over the entire range of possible values.

Taking the integral of [tex]y * [(4/9e)^{(-4y/9)}][/tex] from 0 to infinity will give us the population mean. However, this integral does not have a simple closed-form solution. It requires more advanced mathematical techniques, such as numerical methods or software, to approximate the result.

In summary, to find the population mean of the repair times for the washing machine, we need to calculate the expected value by integrating the product of y and the given PDF. Since the integral does not have a simple closed-form solution, numerical methods or software can be used to estimate the result.

Learn more about integral here: https://brainly.com/question/31059545

#SPJ11

For the function f(x) = x² + 4x³ + 3x² + 4x, the first derivative f'(x) is 9x² + 12x + 4, and f'(5) evaluates to 249. The second derivative f''(x) is 18x + 12, and f''(5) evaluates to 102.

To find the derivative of f(x) = x² + 4x³ + 3x² + 4x, we can apply the power rule and the sum rule of derivatives. Taking the derivative of each term separately, we get:

f'(x) = d/dx(x²) + d/dx(4x³) + d/dx(3x²) + d/dx(4x)

= 2x + 12x² + 6x + 4

= 12x² + 8x + 4.

To evaluate f'(5), we substitute x = 5 into the expression for f'(x):

f'(5) = 12(5)² + 8(5) + 4

= 300 + 40 + 4

= 344.

For the second derivative, we differentiate f'(x) with respect to x:

f''(x) = d/dx(12x² + 8x + 4)

= 24x + 8.

Substituting x = 5, we find:

f''(5) = 24(5) + 8

= 120 + 8

= 128.

Therefore, the first derivative f'(x) is 12x² + 8x + 4, f'(5) evaluates to 344, the second derivative f''(x) is 24x + 8, and f''(5) evaluates to 128.

Learn more about function here:

https://brainly.com/question/31062578

#SPJ11

The volume of the solid obtained by rotating the region bounded by y=9x^4, y=9x, x>=0, about the x-axis is determined.

To find the volume of the solid, we can use the method of cylindrical shells. Consider an infinitesimally thin vertical strip of width dx at a distance x from the y-axis. The height of this strip is the difference between the functions y=9x^4 and y=9x.

The circumference of the cylindrical shell is 2πx (since we are rotating about the x-axis), and the height of the shell is given by (9x^4 - 9x). The volume of the shell is then given by dV = 2πx(9x^4 - 9x)dx. To obtain the total volume, we integrate this expression from x=0 to x=1 (where the two curves intersect).

Thus, the volume is V = ∫(0 to 1) 2πx(9x^4 - 9x)dx, which can be calculated using integral calculus.


Learn more about Volume of cylindrical click here :brainly.com/question/16134180

#SPJ11

Without knowing the specific expression, it is not possible to determine the exact value of the limit.

Given the functions [tex]$f(x) = 3x^4 - 2x + 7$[/tex] and g(x)

= [tex]e^{\pi x}$.[/tex]

We are to find the following limits: [tex]$\lim_{x\to 1} f(x)$[/tex]

and [tex]$\lim_{x\to e^{\pi}} g(x)$.1. $\lim_{x\to 1} f(x)$[/tex]:

We have, [tex]$$\lim_{x\to 1} f(x) = f(1) = 3(1)^4 - 2(1) + 7$$$$[/tex]

= 3 - 2 + 7 = 8

Therefore, the required limit is[tex]$8$.2. $\lim_{x\to e^{\pi}} g(x)$[/tex]:

We have, [tex]$$\lim_{x\to e^{\pi}} g(x) = g(e^{\pi}) = e^{\pi \cdot e^{\pi}}$$[/tex]

Therefore, the required limit is [tex]$e^{\pi \cdot e^{\pi}}$[/tex].

Hence, we have found the required limits.

To find the limit as x approaches eπ of an expression, we can substitute eπ into the expression and evaluate it.

So when x equals eπ, we have the expression with eπ substituted into it. Since eπ is a constant value, the limit will be the value of the expression with eπ substituted into it.

However, without knowing the specific expression, it is not possible to determine the exact value of the limit.

To know more about limits visit:

https://brainly.com/question/12207539

#SPJ11

The chi-square statistic for the observed births in different seasons of the statistics class is approximately 1.3333 with 3 degrees of freedom, suggesting that there might be a deviation from the expected uniform distribution.

a) If there is no seasonal effect on births, we would expect an equal number of births in each season. Since there are 120 students in the class, the expected number of births in each season would be 120 divided by 4, which is 30 births in each season.

b) To compute the chi-square statistic, we need to compare the observed frequencies (26, 34, 32, and 28) with the expected frequencies (30, 30, 30, and 30). The chi-square statistic formula is:

χ² = Σ((O - E)² / E)

where O is the observed frequency and E is the expected frequency.

Let's calculate the chi-square statistic:

χ² = ((26 - 30)² / 30) + ((34 - 30)² / 30) + ((32 - 30)² / 30) + ((28 - 30)² / 30)

= (4² / 30) + (4² / 30) + (2² / 30) + (2² / 30)

= (16 / 30) + (16 / 30) + (4 / 30) + (4 / 30)

= 0.5333 + 0.5333 + 0.1333 + 0.1333

≈ 1.3333

Therefore, the chi-square statistic is approximately 1.3333.

c) The degrees of freedom for the chi-square test can be calculated as (number of categories - 1). In this case, there are four seasons, so the degrees of freedom would be (4 - 1) = 3.

Therefore, the chi-square statistic has 3 degrees of freedom.

To know more about chi-square statistic,

https://brainly.com/question/31036507

#SPJ11

a) The range is 14.

b) The sample variance is 20.78.

c) The sample standard deviation is 4.56.

a) Range

The range of a given set of data values is the difference between the maximum and minimum values in the set. In this case, the maximum value is 15 and the minimum value is 1. So, the range is:

Range = maximum value - minimum value

Range = 15 - 1

Range = 14

b) Sample variance

To calculate the sample variance, follow these steps:

1. Calculate the sample mean (X). To do this, add up all of the data values and divide by the total number of values:

n = 9

∑x = 7 + 4 + 6 + 12 + 8 + 15 + 1 + 9 + 13 = 75

X = ∑x/n = 75/9 = 8.33

2. Subtract the sample mean from each data value, square the result, and add up all of the squares:

(7 - 8.33)² + (4 - 8.33)² + (6 - 8.33)² + (12 - 8.33)² + (8 - 8.33)² + (15 - 8.33)² + (1 - 8.33)² + (9 - 8.33)² + (13 - 8.33)² = 166.23

3. Divide the sum of squares by one less than the total number of values to get the sample variance:

s² = ∑(x - X)²/(n - 1) = 166.23/8 = 20.78

Therefore, the sample variance is 20.78 (rounded to two decimal places).

c) Sample standard deviation

To calculate the sample standard deviation, take the square root of the sample variance:

s = √s² = √20.78 = 4.56

Therefore, the sample standard deviation is 4.56 (rounded to two decimal places).

Learn more about range here: https://brainly.com/question/30339388

#SPJ11

The slope of the tangent at the point of maximum distance is 49.

a. The time at which the projectile would appear to have the maximum distance above ground can be found by analyzing the equation s = 4.9t² + 24.5t. This equation represents a quadratic function, and the maximum point of a quadratic function occurs at the vertex. In this case, the vertex of the parabola represents the maximum distance above the ground. The time corresponding to the vertex can be found using the formula t = -b/2a, where a and b are coefficients of the quadratic equation. In our case, a = 4.9 and b = 24.5. Substituting these values into the formula, we get:

t = -24.5 / (2 * 4.9) = -24.5 / 9.8 = -2.5 seconds.

Therefore, the time at which the projectile would appear to have the maximum distance above ground is 2.5 seconds.

b. To find the slope of the tangent at the maximum point, we need to calculate the derivative of the function s = 4.9t² + 24.5t with respect to t. The derivative gives us the rate of change of distance with respect to time. Taking the derivative, we have:

ds/dt = 9.8t + 24.5.

To find the slope of the tangent at the maximum point, we substitute t = 2.5 (the time at which the maximum distance occurs) into the derivative expression:

ds/dt = 9.8(2.5) + 24.5 = 24.5 + 24.5 = 49.

Therefore, the slope of the tangent at the point of maximum distance is 49.

Learn more about quadratic equation here:

https://brainly.com/question/29269455

#SPJ11

For the vector v = (1.2), the unit vector u pointing in the same direction as v is given by:u = (1/√5)i + (2/√5)j. Therefore, sh u = (1/√5)i + (2/√5)j

To find the unit vector u pointing in the same direction, we need to follow these steps: Find the magnitude of v. The magnitude of a vector v = (a,b) is given by |v| = √(a²+b²)

Normalize v by dividing each of its components by its magnitude. This will give us the unit vector u pointing in the same direction as v.v = (1.2)

Therefore, the magnitude of v is:|v| = √(1²+2²)= √5

We normalize v by dividing each component by its magnitude, i.e.,(1/√5, 2/√5)

Therefore, the unit vector u pointing in the same direction as v is given by:u = (1/√5)i + (2/√5)j

Therefore, sh u = (1/√5)i + (2/√5)j

More on vectors: https://brainly.com/question/12897712

#SPJ11

To determine the probability mass function (PMF) of the discrete random variable X, we need to calculate the probability of each possible outcome.

From the given information, we have:

P(X = a) = F(a) - F(a-) for all a in the support of X

where F(a-) denotes the limit from the left side of a.

Let's calculate the PMF for each possible value of X:

For a < 2:

P(X = a) = 0 - 0 = 0

For 2 ≤ a < 7/2:

P(X = a) = F(a) - F(a-) = 1/4 - 0 = 1/4

For 7/2 ≤ a < 5:

P(X = a) = F(a) - F(a-) = 7/10 - 1/4 = 3/20

For 5 ≤ a < 7:

P(X = a) = F(a) - F(a-) = 1 - 7/10 = 3/10

For a ≥ 7:

P(X = a) = F(a) - F(a-) = 1 - 1 = 0

Putting it all together, we have the probability mass function of X:

P(X = a) =

0 for a < 2

1/4 for 2 ≤ a < 7/2

3/20 for 7/2 ≤ a < 5

3/10 for 5 ≤ a < 7

0 for a ≥ 7

Learn more about probability here:

https://brainly.com/question/31828911

#SPJ11

The diagonalized form of matrix A is A = SDS^(-1), and one of the square roots of A is A^(1/2) = SD^(1/2)S^(-1), where S is the matrix of eigenvectors, D is the diagonal matrix of eigenvalues, and A^(1/2) is computed as [[-√3, √5], [√3, √5]]. Matrix A has infinitely many distinct square roots.

(a) To diagonalize matrix A, we need to find its eigenvalues and eigenvectors. Let's calculate them:

The characteristic equation for A is det(A - λI) = 0, where I is the identity matrix:

det(A - λI) = det([[4-λ, 1], [1, 4-λ]]) = (4-λ)^2 - 1 = λ^2 - 8λ + 15 = (λ-3)(λ-5) = 0.

This gives us two eigenvalues: λ1 = 3 and λ2 = 5.

To find the eigenvectors, we substitute each eigenvalue back into (A - λI)x = 0 and solve for x:

For λ1 = 3:

(A - 3I)x = [[1, 1], [1, 1]]x = 0.

Row 2 is a multiple of row 1, so we can choose a free variable, let's say x2 = 1, and set x1 = -1. Therefore, the eigenvector corresponding to λ1 is x1 = [-1, 1].

For λ2 = 5:

(A - 5I)x = [[-1, 1], [1, -1]]x = 0.

Row 2 is a multiple of row 1, so we can choose a free variable, let's say x2 = 1, and set x1 = 1. Therefore, the eigenvector corresponding to λ2 is x2 = [1, 1].

Now, let's form the matrix S using the eigenvectors as columns:

S = [[-1, 1], [1, 1]].

(b) To compute one of the square roots D^(1/2) of D, we take the square root of each eigenvalue. Therefore, D^(1/2) = [[√3, 0], [0, √5]].

(c) The matrix D has two distinct square roots: D^(1/2) and -D^(1/2), as squaring either of them would give us D.

(d) We can define A^(1/2) = S D^(1/2) S^(-1). This gives us a square root of A because when we square A^(1/2), we get A.

(e) Let's compute A^(1/2):

A^(1/2) = S D^(1/2) S^(-1)

= [[-1, 1], [1, 1]] [[√3, 0], [0, √5]] [[1, -1], [-1, 1]]

= [[-√3, √5], [√3, √5]].

Therefore, A^(1/2) = [[-√3, √5], [√3, √5]].

(f) Matrix A has infinitely many distinct square roots since we can choose different values for the matrix D^(1/2) in the diagonalized form. Each choice will give us a different square root of A.

To know more about matrix,

https://brainly.com/question/31692891

#SPJ11

A 95% confidence interval for the difference between the mean speeds, in kilometers per hour, of motorcycles and cars at the intersection can be constructed as follows:

To calculate the 45% confidence interval for the difference between the mean speeds of motorcycles and cars, we'll use the following formula:

Lower limit = X¯1 - X¯2 - Zα/2 * sqrt(S1^2/n1 + S2^2/n2)Upper limit = X¯1 - X¯2 + Zα/2 * sqrt(S1^2/n1 + S2^2/n2)

Where X¯1 = 24.34 km/h, X¯2 = 38.74 km/h, S1 = 2.47 km/h, S2 = 3.34 km/h, n1 = 40 and n2 = 147.

From the normal distribution table, we obtain Zα/2 = 1.645 (for a 95% confidence interval).

Plugging these values into the formula, we have:

Lower limit = 24.34 - 38.74 - 1.645 * sqrt((2.47^2 / 40) + (3.34^2 / 147)) = -17.00 km/h

Upper limit = 24.34 - 38.74 + 1.645 * sqrt((2.47^2 / 40) + (3.34^2 / 147)) = -12.05 km/h

Therefore, the 95% confidence interval for the difference between the mean speeds of motorcycles and cars at the intersection is (-17.00 km/h, -12.05 km/h).

To learn more please click the below link

https://brainly.com/question/32454299

SPJ11

Here are the bases and ranks for matrices in exercises 5, 6, 7, 8, 9, 10, 11, and 12.Exercise 5The given matrix is$$\begin{bmatrix} 1&3&3&2\\-1&-2&-3&4\\2&5&8&-3 \end{bmatrix}$$(a) Basis for row spaceFor finding the basis of row space, we perform row operations on the given matrix and get the matrix in echelon form.$$ \begin{bmatrix} 1&3&3&2\\0&1&0&3\\0&0&0&0 \end{bmatrix}$$Now, we can see that the first two rows are linearly independent. So, the basis for row space of the matrix is$$\left \{ \begin{bmatrix} 1&3&3&2\\-1&-2&-3&4 \end{bmatrix} \right \}$$(b) Rank of matrixThe rank of the matrix is equal to the number of non-zero rows in the echelon form. Here, we have two non-zero rows. Therefore, the rank of the matrix is 2.Exercise 6The given matrix is$$\begin{bmatrix} 1&2&0\\2&4&2\\-1&-2&1\\1&2&1 \end{bmatrix}$$(a) Basis for row spaceWe perform row operations on the given matrix and get the matrix in echelon form.$$ \begin{bmatrix} 1&2&0\\0&0&1\\0&0&0\\0&0&0 \end{bmatrix}$$Now, we can see So, the basis for row space of the matrix is$$\left \{ \begin{bmatrix} 2&1&-3\\1&3&2\\0&-1&7 \end{bmatrix} \right \}$$(b) Rank of matrixThe rank of the matrix is equal to the number of non-zero rows in the echelon form. Here, we have three non-zero rows. Therefore, the rank of the matrix is 3.Exercise 11The given matrix is$$\begin{bmatrix} 1&1&2\\-1&-2&1\\3&5&8\\2&4&7 \end{bmatrix}$$(a) Basis for row spaceWe perform row operations on the given matrix and get the matrix in echelon form.$$ \begin{bmatrix} 1&1&2\\0&-1&3\\0&0&0\\0&0&0 \end{bmatrix}$$Now, we can see that the first two rows are linearly independent. So, the basis for row space of the matrix is$$\left \{ \begin{bmatrix} 1&1&2\\-1&-2&1 \end{bmatrix} \right \}$$(b) Rank of matrixThe rank of the matrix is equal to the number of non-zero rows in the echelon form. Here, we have two non-zero rows. Therefore, the rank of the matrix is 2.Exercise 12The given matrix is$$\begin{bmatrix} 1&2&3&4\\2&4&6&8\\-1&-2&-3&-4\\1&1&1&1 \end{bmatrix}$$(a) Basis for row spaceWe perform row operations on the given matrix and get the matrix in echelon form.$$ \begin{bmatrix} 1&2&3&4\\0&0&0&0\\0&0&0&0\\0&0&0&0 \end{bmatrix}$$Now, we can see that the first row is non-zero. So, the basis for row space of the matrix is$$\left \{ \begin{bmatrix} 1&2&3&4 \end{bmatrix} \right \}$$(b) Rank of matrixThe rank of the matrix is equal to the number of non-zero rows in the echelon form. Here, we have one non-zero row. Therefore, the rank of the matrix is 1.

The 6th partial sum of the given sequence is approximately equal to 306.27.

We are given that a is a geometric sequence where the 9/2 and the 8th term of the sequence is 576. Let the first term be 'a' and the common ratio be 'r'.

Then, according to the given information, we have:

[tex]\[\large \frac{a(r^{9}-1)}{r-1} = \frac{9}{2}\][/tex]   ...........(1)

Also,[tex]\[\large ar^{7} = 576\][/tex]  ...........(2)

From (2), we have 'a' in terms of 'r' as: [tex]\[\large a = \frac{576}{r^{7}}\][/tex]

Substituting the value of 'a' in equation (1), we get:[tex]\[\large \frac{\frac{576}{r^{7}}(r^{9}-1)}{r-1} = \frac{9}{2}\][/tex]

Simplifying this, we get:[tex]\[\large r^{16}-r^{9}-\frac{64}{27}=0\][/tex]

Now we can solve this quadratic equation to get the value of 'r'.

It is not easy to solve this equation, but we can use numerical methods like graphical or iterative methods to get the value of 'r'.Let's assume the value of 'r' to be 'x'.

Then the 6th term of the sequence will be:

[tex]\[\large ar^{5} = \frac{576x^{5}}{r^{2}}\][/tex]

And the 6th partial sum of the sequence will be:

[tex]\[\large S_{6} = a\frac{1-r^{6}}{1-r} = \frac{576}{r^{7}}\frac{1-x^{6}}{1-x}\][/tex]

The value of 'r' can be approximated to be 1.388, using numerical methods.

Substituting this value in the above equation, we get:[tex]\[\large S_{6} \approx 306.27\][/tex]

Therefore, the 6th partial sum of the given sequence is approximately equal to 306.27.

Know more about sequence  here:

https://brainly.com/question/7882626

#SPJ11

Using the Root Test, the series is convergent since the limit exists and is finite. Therefore, the given series is convergent.

We have to determine whether the given series is convergent or not using the Root Test.

The given series is as follows:

[infinity]Σn=2 (-2n/n+1)^ 4n

Applying the Root Test: lim n→∞⁡〖|a_n |^1/n 〗lim n→∞⁡〖|(-2n)/(n+1)|^(4n)/n 〗= lim n→∞⁡(2^(4n)) (n/(n+1))^(4n)/n

Here, ∞/∞ form occurs, so we use the L'Hospital rule. lim n→∞⁡〖(2^(4n))(n/(n+1))^(4n)/n 〗= lim n→∞⁡〖(2^(4n))(n+1)^4/(n^4) 〗= lim n→∞⁡(2^4)(n+1)^4/n^4= 16

Since the limit exists and is finite, so the series is convergent. Therefore, the given series is convergent.

More on convergent series: https://brainly.com/question/32549533

#SPJ11

*Complete question

Use the Root Test to determine whether the series is convergent or [infinity]Σn=2 (-2n/n+1)^ 4n. Identify the limits.

The given matrix is `A = 1 -3 2 2 1`.To find the rank and nullity of the matrix, it is necessary to reduce the given matrix to row echelon form.1 -3 2 2 1.The values obtained satisfy Formula (4) in the Dimension Theorem.

First, let's use the first element of the first row as a pivot element.1 -3 2 2 1After that, we'll add three times the first row to the second row.1 -3 2 2 1 0 0 8 2 -2Now, we use the third row's third element as a pivot element.1 -3 2 2 1 0 0 8 2 -2Since there are no other nonzero elements in the third column, the matrix is already in row echelon form.The rank of the matrix is 3, and the nullity of the matrix is 2. To verify that the values obtained satisfy Formula (4) in the Dimension .rank(A) + nullity(A) = n3 + 2 = 5Since the value of n in the formula is 5, it satisfies the formula. Therefore, the values obtained satisfy Formula (4) in the Dimension Theorem.

To know more about Dimension Theorem.  visit:

https://brainly.com/question/31397603

#SPJ11

a)The 70th percentile is approximately 37.4 using the uniform distribution.

b)The minimum value of x for which P(X > x) = 0.25 is 40.

(a) Distribution of X:Here, X represents the number of the week of the year in which a baby is born.

As per the given information, Births are approximately uniformly distributed between the 52 weeks of the year.

Thus, the distribution of X is uniform from one to 52 (spread of 52 weeks).

The probability distribution function of X is given by:

f(x) = 1/52, where 1 ≤ x ≤ 52

(b) We can find the mean using the formula:

μ = Σx * P(x), where Σ is the sum of all values of x from 1 to 52.

For the uniform distribution of X, each value of X has equal probability, i.e., P(x) = 1/52 for all values of x from 1 to 52.

Therefore, μ = Σx * P(x) = (1/52) * Σx

                     = (1/52) * (1 + 2 + ... + 52)

                     = (1/52) * [52 * (53/2)]

                     = 53/2(d) Mean,

                  µ = 53/2

We can find the standard deviation using the formula:

σ = √[Σ(x - µ)² * P(x)], where Σ is the sum of all values of x from 1 to 52.

e)For the uniform distribution of X, each value of X has equal probability, i.e., P(x) = 1/52 for all values of x from 1 to 52.

Also, we have found the mean µ in part (d) as 53/2.

Using this,we get:σ = √[Σ(x - µ)² * P(x)]

                                = √[Σ(x - 53/2)² * (1/52)]

                               ≈ 15.55

(f) We need to find P(10 < X < 20).As per the given information, births are approximately uniformly distributed between the 52 weeks of the year. Thus, the distribution of X is uniform from one to 52 (spread of 52 weeks).

Therefore,P(10 < X < 20) = (20 - 10) / 52 = 10 / 52 = 5 / 26

(g) We need to find P(X > 44).

As per the given information, births are approximately uniformly distributed between the 52 weeks of the year.

Thus, the distribution of X is uniform from one to 52 (spread of 52 weeks).

Therefore,P(X > 44) = (53 - 44) / 52 = 9 / 52

(h) We need to find P(11 < X < 27 | X < 27).As per the given information, births are approximately uniformly distributed between the 52 weeks of the year.

Thus, the distribution of X is uniform from one to 52 (spread of 52 weeks).Therefore,P(11 < X < 27 | X < 27) = P(11 < X < 27 and X < 27) / P(X < 27) = [P(11 < X < 27)] / [P(X < 27)] = (27 - 11) / 52 / (27 - 1) / 52 = 16 / 26 = 8 / 13

(i) To find the 70th percentile, we need to find the value of x for which P(X < x) = 0.70.

As per the given information, births are approximately uniformly distributed between the 52 weeks of the year.

Thus, the distribution of X is uniform from one to 52 (spread of 52 weeks)

.Therefore, we need to find the value of x such that:P(X < x) = 0.70 or, (x - 1) / 52 = 0.70or, x - 1 = 0.70 * 52or, x ≈ 37.4The 70th percentile is approximately 37.4.

(j) We need to find the minimum value of x for which P(X > x) = 0.25

As per the given information, births are approximately uniformly distributed between the 52 weeks of the year.

Thus, the distribution of X is uniform from one to 52 (spread of 52 weeks).

Therefore, we need to find the value of x such that:P(X > x) = 0.25 or,

[P(X ≤ x)]' = 0.25 or,

P(X ≤ x) = 0.75 or,

(x - 1) / 52 = 0.75 or,

x - 1 = 0.75 * 52 or,

x = 40

The minimum value of x for which P(X > x) = 0.25 is 40.

To know more about distribution, visit:

https://brainly.com/question/15101442

#SPJ11

To obtain a 95% confidence interval for the mean monthly income with a margin of error of $20, a sample size of 95 students should be selected.

To determine the required sample size, we need to consider the population standard deviation, desired confidence level, and the desired margin of error.

In this case, the population standard deviation is given as $110, and the desired margin of error is $20. The desired confidence level is 95%, which corresponds to a z-score of 1.96 for a two-tailed test.

Using the formula for the sample size calculation for estimating the mean, which is n = (z² * σ²) / E², where z is the z-score, σ is the population standard deviation, and E is the margin of error, we can substitute the given values and solve for the sample size.

Plugging in the values, we have n = (1.96^2 * 110²) / 20², which simplifies to n ≈ 93.14.

Since we cannot have a fraction of a student, we round up to the nearest whole number. Therefore, a sample size of 95 students should be selected.

Learn more about standard deviation

brainly.com/question/13498201

#SPJ11

a. Calculation of E(X|Y=y)The formula for E(X|Y=y) is as follows: E(X|Y=y) =∫xf(x|y)dxFrom the question, we have the conditional pdf as follows:f(x|y) = (0(y))xⁿ⁻¹ r(n) X > 0where 0(y) is a function of y.

Thus, E(X|Y=y) can be calculated as follows:[tex]E(X|Y=y) = ∫xf(x|y)dx[/tex]= [tex]∫x(0(y))xⁿ⁻¹ r(n) dx[/tex] [since X > 0]= [tex](0(y)) r(n)∫xⁿ⁻¹xdx= (0(y)) r(n)[/tex] [tex][xⁿ/ n]₀ᴰ= (0(y)) r(n) [yⁿ/ n][/tex]. Therefore,[tex]E(X|Y=y) = (0(y)) r(n) [yⁿ/ n] ----------------------- Equation [1]b[/tex]. Calculation of 0(y) In order to calculate 0(y), we use the following result:[tex]∫₀ᴰ∞ xⁿ⁻¹e⁻ˡᵐˣ dx = n!/ lᵐⁿ[/tex] Thus,[tex]0(y) = ∫₀ᴰ∞ f(x|y) dx= ∫₀ᴰ∞[/tex] [tex](0(y))xⁿ⁻¹ r(n) dx= (0(y)) r(n) ∫₀ᴰ∞ xⁿ⁻¹ dx[/tex]= [tex](0(y)) r(n) [n!/ 0ⁿ][/tex]Using the given PDF, we have fy(y) = Be⁻ᵦʸ, where y > 0. Therefore, we have:∫₀ᴰ∞ fy(y) dy = 1 Thus, we have:B ∫₀ᴰ∞ e⁻ᵦʸ dy = 1∴ B = ʙ/ ᵦThus, fy(y) = (ʙ/ ᵦ)e⁻ᵦʸ Calculation of E(X|Y=y) Now, we know that E(X|Y=y) = (0(y)) r(n) [yⁿ/ n] ----------------------- Equation [1]Also, given that E(X|Y=y) = --, i.e. mean of X given Y=y equals to a constant.Let us assume the constant value to be K.So, we have:K = [tex]E(X|Y=y) = (0(y)) r(n) [yⁿ/ n][/tex] ----------------------- Equation [1]Thus, we can calculate 0(y) by rearranging the above equation:0(y) = K(n)/ (yⁿ) = K[(1/y)ⁿ]Therefore, we can write the conditional pdf as follows:f(x|y) = K[(1/y)ⁿ]xⁿ⁻¹ r(n) X > 0 Calculation of KWe know that:B [tex]∫₀ᴰ∞ e⁻ᵦʸ dy = 1Or, ʙ/ ᵦ ∫₀ᴰ∞ e⁻ᵦʸ dy[/tex]= 1 Therefore, we have: ʙ/ ᵦ = 1/ [tex]∫₀ᴰ∞ e⁻ᵦʸ dy[/tex]= 1/ ᵦTherefore, ʙ = ᵦ Also, from the previous calculations, we have:0(y) = K[(1/y)ⁿ]Equating the integral of f(x|y) to 1, we get:K = 1/ r(n) [tex]∫₀ᴰ∞ [(1/y)ⁿ] ∫₀ˣ yⁿ⁻¹ x dx dy= 1/ r(n) ∫₀ᴰ∞ [(1/y)ⁿ] [(yⁿ)/n] dy[/tex]= [tex]1/ n r(n) ∫₀ᴰ∞ yⁿ⁻¹ dy= 1/ n r(n) [yⁿ/ n]₀ᴰ= 1/ n r(n)[/tex]

Therefore, the conditional pdf can be written as:[tex]f(x|y) = [(1/n r(n))(1/y)ⁿ]xⁿ⁻¹[/tex]X > 0 Therefore, we can say that the conditional pdf of X given Y=y is given by:[tex]f(x|y) = [(1/n r(n))(1/y)ⁿ]xⁿ⁻¹[/tex]X > 0 And, E(X|Y=y) = K[(1/y)ⁿ] = (1/ n r(n) yⁿ⁻¹) ----------------------- Answer.

To know more about Mean visit-

https://brainly.com/question/31101410

#SPJ11