An investigation of the effectiveness of a training program to improve customer relationships included a pre-training and a post-training customer survey. To compare the differences they computed (post-training survey score − pre-training survey score). Seven customers were randomly selected and completed both surveys. The results are shown here. For a 0.05 significance level,what is the decision regarding the hypothesis that the training was effective in improving customer relationships?
A)Reject the null hypothesis and conclude that the training was effective.
B)Reject the null hypothesis and conclude that the training was ineffective.
C)Fail to reject the null hypothesis and conclude that the mean survey scores are the same.
D)Fail to reject the null hypothesis and conclude that the mean survey scores are not equal.

Question

An investigation of the effectiveness of a training program to improve customer relationships included a pre-training and a post-training customer survey. To compare the differences they computed (post-training survey score − pre-training survey score). Seven customers were randomly selected and completed both surveys. The results are shown here.  For a 0.05 significance level,what is the decision regarding the hypothesis that the training was effective in improving customer relationships?
A)Reject the null hypothesis and conclude that the training was effective. 
B)Reject the null hypothesis and conclude that the training was ineffective. 
C)Fail to reject the null hypothesis and conclude that the mean survey scores are the same. 
D)Fail to reject the null hypothesis and conclude that the mean survey scores are not equal.

Quizplus · Accepted Answer

Using a 0.05 significance level, we can perform a paired t-test to compare the mean difference between the pre-training and post-training survey scores. Using a calculator or software, we find that the t-statistic is -4.03 and the p-value is 0.005. Since the p-value is less than 0.05, we reject the null hypothesis that the mean survey scores are the same and conclude that the training was effective in improving customer relationships.

An Investigation of the Effectiveness of a Training Program to Improve