Question

Exhibit 4

The manager of the service department of a local car dealership has
noted that the service times of a sample of 15 new automobiles has
a sample standard deviation of S = 4 hours. We are interested to
test the following hypotheses using α = 0.05 level of
significance:

H0
: σ2 ≤ 14

Ha
: σ2 > 14

a. Refer to Exhibit 4. Assuming that the population of service times follows an approximately normal distribution, what is the value of the test statistic?

A. 4

B. 14

C. 15

D. 16

b. Refer to Exhibit 4. Assuming that the population of service times follows an approximately normal distribution, what is the p-value?

A. More than 0.10

B. Between 0.05 and 0.10

C. Less than 0.01

D. between 0.025 and 0.05

c. Refer to Exhibit 4. Assuming that the population of service times follows an approximately normal distribution, what is the conclusion?

A. Reject the null hypothesis at α = 0.05 . The
sample supports the alternative hypothesis that the population
variance of the service times exceeds 14.

B. We cannot reject the null hypothesis at α = 0.05 .
The sample does not support the alternative hypothesis that the
population variance of the service times exceeds 14.

C. We can reject the null hypothesis only if the level of
significance, α, is reduced from 0.05 to
0.01.

D. The test is inconclusive.

Answer #1

**Answer:**

As the population of service times follows an approximately normal distribution, the propoer test statistic is Chi Square with degree of freedom = 15-1 = 14

a) Test statistic is,

= **16**

b) P-value = P( > 16) = 0.3134

Since, p-value is greater than 0.05 significance level, we fail to reject null hypothesis H0 and conclude that there is no sufficient evidence that population variance is greater than 14 hours.

c)

Reject the null hypothesis at α = 0.05 . The sample supports the alternative hypothesis that the population variance of the service times exceeds 14.

**NOTE:: I HOPE THIS ANSWER IS HELPFULL TO
YOU......**PLEASE SUPPORT ME WITH YOUR RATING......**

****PLEASE GIVE ME "LIKE".....ITS VERY
IMPORTANT FOR,ME......PLEASE SUPPORT ME .......THANK
YOU**

Exhibit 4 (Questions 19-22)
The manager of the service department of a local car dealership
has noted that the service times of a sample of 15
new automobiles has a sample standard deviation of S =
4 hours. We are interested to test the following
hypotheses using α = 0.05 level of
significance:
H0 : σ2 ≤ 14
Ha : σ2 > 14
Refer to Exhibit 4. Assuming that the
population of service times follows an approximately normal
distribution, what...

The manager of a supermarket would like the variance of the
waiting times of the customers not to exceed 3.7 minutes-squared.
She would add a new cash register if the variance exceeds this
threshold. She regularly checks the waiting times of the customers
to ensure that the variance does not rise above the allowed level.
In a recent random sample of 35 customer waiting times, she
computes the sample variance as 5.8 minutes-squared. She believes
that the waiting times are...

A random sample of
n1 = 49
measurements from a population with population standard
deviation
σ1 = 3
had a sample mean of
x1 = 13.
An independent random sample of
n2 = 64
measurements from a second population with population standard
deviation
σ2 = 4
had a sample mean of
x2 = 15.
Test the claim that the population means are different. Use
level of significance 0.01.
(a) Check Requirements: What distribution does the sample test
statistic follow? Explain....

A random sample of
n1 = 49
measurements from a population with population standard
deviation
σ1 = 5
had a sample mean of
x1 = 8.
An independent random sample of
n2 = 64
measurements from a second population with population standard
deviation
σ2 = 6
had a sample mean of
x2 = 11.
Test the claim that the population means are different. Use
level of significance 0.01.(a) Check Requirements: What
distribution does the sample test statistic follow? Explain.
The...

Let x represent the average annual salary of college
and university professors (in thousands of dollars) in the United
States. For all colleges and universities in the United States, the
population variance of x is approximately
σ2 = 47.1. However, a random sample of 18
colleges and universities in Kansas showed that x has a
sample variance s2 = 78.4. Use a 5% level of
significance to test the claim that the variance for colleges and
universities in Kansas is...

Let x = age in years of a rural Quebec woman at the
time of her first marriage. In the year 1941, the population
variance of x was approximately σ2 =
5.1. Suppose a recent study of age at first marriage for a random
sample of 41 women in rural Quebec gave a sample variance
s2 = 3.0. Use a 5% level of significance to
test the claim that the current variance is less than 5.1. Find a
90% confidence...

Let x = age in years of a rural Quebec woman at the time of her
first marriage. In the year 1941, the population variance of x was
approximately σ2 = 5.1. Suppose a recent study of age at first
marriage for a random sample of 51 women in rural Quebec gave a
sample variance s2 = 2.9. Use a 5% level of significance to test
the claim that the current variance is less than 5.1. Find a 90%
confidence...

Let x = age in years of a rural Quebec woman at the
time of her first marriage. In the year 1941, the population
variance of x was approximately σ2 =
5.1. Suppose a recent study of age at first marriage for a random
sample of 51 women in rural Quebec gave a sample variance
s2 = 3.1. Use a 5% level of significance to
test the claim that the current variance is less than 5.1. Find a
90% confidence...

Let x represent the number of mountain climbers killed
each year. The long-term variance of x is approximately
σ2 = 136.2. Suppose that for the past 11 years,
the variance has been s2 = 107.1. Use a 1%
level of significance to test the claim that the recent variance
for number of mountain-climber deaths is less than 136.2. Find a
90% confidence interval for the population variance.
(a) What is the level of significance?
State the null and alternate hypotheses....

Let x = age in years of a rural Quebec woman at the time of her
first marriage. In the year 1941, the population variance of x was
approximately σ2 = 5.1. Suppose a recent study of age at first
marriage for a random sample of 31 women in rural Quebec gave a
sample variance s2 = 2.6. Use a 5% level of significance to test
the claim that the current variance is less than 5.1. Find a 90%
confidence...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 46 seconds ago

asked 2 minutes ago

asked 4 minutes ago

asked 5 minutes ago

asked 5 minutes ago

asked 7 minutes ago

asked 11 minutes ago

asked 11 minutes ago

asked 12 minutes ago

asked 14 minutes ago

asked 14 minutes ago

asked 14 minutes ago