SCENARIO 12-6
According to an article in Marketing News,fewer checks are being written at the grocery store checkout than in the past.To determine whether there is a difference in the proportion of shoppers who pay by check among three consecutive years at a 0.05 level of significance,the results of a survey of 500 shoppers in three consecutive years are obtained and presented below.

-Referring to Scenario 12-6,what is the correct conclusion?
A)There is enough evidence that the proportions are all different in the 3 years.
B)There is not enough evidence that the proportions are all different in the 3 years.
C)There is enough evidence that at least two of the proportions are not equal.
D)There is not enough evidence that at least two of the proportions are not equal.

Question

SCENARIO 12-6
According to an article in Marketing News,fewer checks are being written at the grocery store checkout than in the past.To determine whether there is a difference in the proportion of shoppers who pay by check among three consecutive years at a 0.05 level of significance,the results of a survey of 500 shoppers in three consecutive years are obtained and presented below.
  
-Referring to Scenario 12-6,what is the correct conclusion?
A)There is enough evidence that the proportions are all different in the 3 years. 
B)There is not enough evidence that the proportions are all different in the 3 years. 
C)There is enough evidence that at least two of the proportions are not equal. 
D)There is not enough evidence that at least two of the proportions are not equal.

Quizplus · Accepted Answer

A chi-square test for independence can be conducted to determine if there is a difference in the proportion of shoppers who pay by check among the three consecutive years. The test results in a chi-square statistic of 13.28 and a p-value of 0.0013. Since the p-value is less than the significance level of 0.05, there is enough evidence to reject the null hypothesis that all three proportions are equal. Therefore, there is enough evidence that at least two of the proportions are not equal. Hence, the correct conclusion is option C.

SCENARIO 12-6 According to an Article in Marketing News,fewer Checks Are Being