TABLE 10-13
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 10-13, 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.

Question

TABLE 10-13
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 10-13, 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.

Quizplus · Accepted Answer

To test for a difference in the variability (i.e. variances) between two populations, we need the following assumptions:
A) Both sampled populations are normally distributed (for large sample sizes, we can use the Central Limit Theorem).
B) Both samples are random and independent.

TABLE 10-13 The Amount of Time Required to Reach a Customer Service