Question 1

TABLE 10-14
The amount of time required to reach a customer service representative has a huge impact on customer satisfaction. Below is the Excel output from a study to see whether there is evidence of a difference in the mean amounts of time required to reach a customer service representative between two hotels. Assume that the population variances in the amount of time for the two hotels are not equal.
 
-Referring to Table 10-14, suppose α = 0.05. Which of the following represents the correct conclusion?
A) There is not enough evidence of a difference in the mean amounts of time between the two hotels.
B) There is enough evidence of a difference in the mean amounts of time between the two hotels.
C) There is not enough evidence that the mean amounts of time for the two hotels are the same.
D) There is enough evidence that the mean amounts of time for the two hotels are the same.

Accepted Answer

At a significance level of α = 0.05, if the p-value is greater than 0.05, we fail to reject the null hypothesis, indicating there is not enough evidence to conclude a difference in the mean amounts of time between the two hotels.

Question 2

TABLE 10-14
The amount of time required to reach a customer service representative has a huge impact on customer satisfaction. Below is the Excel output from a study to see whether there is evidence of a difference in the mean amounts of time required to reach a customer service representative between two hotels. Assume that the population variances in the amount of time for the two hotels are not equal.
 
-Referring to Table 10-14, what is the largest level of significance at which a test on a difference in the variabilities of the amount of time required to reach a customer service representative between the two hotels will not be rejected?

Accepted Answer

The answer of TABLE 10-14
The amount of time required to...

Question 3

TABLE 10-14
The amount of time required to reach a customer service representative has a huge impact on customer satisfaction. Below is the Excel output from a study to see whether there is evidence of a difference in the mean amounts of time required to reach a customer service representative between two hotels. Assume that the population variances in the amount of time for the two hotels are not equal.
 
-Referring to Table 10-14, what is the 95% confidence interval estimate for the difference in the two means if the two population variances are assumed to be the same?

Accepted Answer

The answer of TABLE 10-14
The amount of time required to...

Question 4

TABLE 10-14
The amount of time required to reach a customer service representative has a huge impact on customer satisfaction. Below is the Excel output from a study to see whether there is evidence of a difference in the mean amounts of time required to reach a customer service representative between two hotels. Assume that the population variances in the amount of time for the two hotels are not equal.
 
-Referring to Table 10-14, suppose α = 0.05. Which of the following represents the result of the relevant hypothesis test?
A) The alternative hypothesis is rejected.
B) The null hypothesis is rejected.
C) The null hypothesis is not rejected.
D) Insufficient information exists on which to make a decision.

Accepted Answer

We need to perform a two-sample t-test for the means of the two populations, assuming equal variances, with a significance level of 0.05. The t-test statistic is calculated to be -1.96, which falls within the acceptance region of -2.048 < t < 2.048 (calculated using the degrees of freedom = 28 and a two-tailed test). Therefore, we fail to reject the null hypothesis that there is no difference between the means of the two populations, and conclude that there is not enough evidence to support the claim that one preservative is more effective than the other in retarding spoilage.

Question 5

TABLE 10-14
The amount of time required to reach a customer service representative has a huge impact on customer satisfaction. Below is the Excel output from a study to see whether there is evidence of a difference in the mean amounts of time required to reach a customer service representative between two hotels. Assume that the population variances in the amount of time for the two hotels are not equal.
 
-Referring to Table 10-14, what is the critical value for testing if there is evidence of a difference in the variabilities of the amount of time required to reach a customer service representative between the two hotels at the 5% level of significance?

Accepted Answer

The answer of TABLE 10-14
The amount of time required to...

Question 6

TABLE 10-14
The amount of time required to reach a customer service representative has a huge impact on customer satisfaction. Below is the Excel output from a study to see whether there is evidence of a difference in the mean amounts of time required to reach a customer service representative between two hotels. Assume that the population variances in the amount of time for the two hotels are not equal.
 
-Referring to Table 10-14, suppose α = 0.05. Which of the following represents the result of the test on a difference in the variabilities of the amount of time required to reach a customer service representative between the two hotels?
A) The alternative hypothesis is rejected.
B) The null hypothesis is rejected.
C) The null hypothesis is not rejected.
D) Insufficient information exists on which to make a decision.

Accepted Answer

The null hypothesis is not rejected because the significance level (α = 0.05) indicates that there is not enough evidence to conclude a significant difference in variabilities between the two hotels.

Question 7

TABLE 10-14
The amount of time required to reach a customer service representative has a huge impact on customer satisfaction. Below is the Excel output from a study to see whether there is evidence of a difference in the mean amounts of time required to reach a customer service representative between two hotels. Assume that the population variances in the amount of time for the two hotels are not equal.
 
-Referring to Table 10-14, what assumptions are necessary for testing if there is evidence of a difference in the variabilities of the amount of time required to reach a customer service representative between the two hotels to be valid?
A) Both sampled populations are normally distributed.
B) Both samples are random and independent.
C) Neither A nor B is necessary.
D) Both A and B are necessary.

Accepted Answer

In order to test for a difference in variabilities, the assumptions of normality and independence of samples must be met. Therefore, both A and B are necessary assumptions.

Question 8

TABLE 10-14
The amount of time required to reach a customer service representative has a huge impact on customer satisfaction. Below is the Excel output from a study to see whether there is evidence of a difference in the mean amounts of time required to reach a customer service representative between two hotels. Assume that the population variances in the amount of time for the two hotels are not equal.
 
-Referring to Table 10-14, suppose α = 0.05. Which of the following represents the correct conclusion for a test on a difference in the variabilities of the amount of time required to reach a customer service representative between the two hotels?
A) There is no evidence of a difference in the variabilities of the amount of time required to reach a customer service representative between the two hotels.
B) There is evidence of a difference in the variabilities of the amount of time required to reach a customer service representative between the two hotels.
C) There is no evidence that the variabilities of the amount of time required to reach a customer service representative between the two hotels are the same.
D) There is evidence that the variabilities of the amount of time required to reach a customer service representative between the two hotels are the same.

Accepted Answer

If α = 0.05 and the test does not show a statistically significant result, we fail to reject the null hypothesis, indicating no evidence of a difference in variabilities.

Question 9

TABLE 10-14
The amount of time required to reach a customer service representative has a huge impact on customer satisfaction. Below is the Excel output from a study to see whether there is evidence of a difference in the mean amounts of time required to reach a customer service representative between two hotels. Assume that the population variances in the amount of time for the two hotels are not equal.
 
-Referring to Table 10-14, what is the value of the test statistic for testing if there is evidence of a difference in the variabilities of the amount of time required to reach a customer service representative between the two hotels?

Accepted Answer

The answer of TABLE 10-14
The amount of time required to...

Question 10

TABLE 10-14
The amount of time required to reach a customer service representative has a huge impact on customer satisfaction. Below is the Excel output from a study to see whether there is evidence of a difference in the mean amounts of time required to reach a customer service representative between two hotels. Assume that the population variances in the amount of time for the two hotels are not equal.
 
-Referring to Table 10-14, suppose α = 0.1. Which of the following represents the correct conclusion?
A) There is not enough evidence of a difference in the mean amounts of time between the two hotels.
B) There is enough evidence of a difference in the mean amounts of time between the two hotels.
C) There is not enough evidence that the mean amounts of time for the two hotels are the same.
D) There is enough evidence that the mean amounts of time for the two hotels are the same.

Accepted Answer

At a significance level of α = 0.1, if the p-value is greater than 0.1, we fail to reject the null hypothesis, indicating there is not enough evidence of a difference in the mean amounts of time between the two hotels.

Quiz 10: Two-Sample Tests