A company that produces financial accounting software wants to offer better training to its customers. The training is intended to decrease the amount of time required to do complicated accounting calculations. For seven individuals, the amount of time (in minutes) to complete a complicated calculation is determined before and after completing the new training. Using the critical value approach and α = 0.05, the appropriate conclusion is ________.
A) reject the null hypothesis; we cannot conclude the median difference of the times is greater than zero
B) reject the null hypothesis; we can conclude the median difference of the times is greater than zero
C) do not reject the null hypothesis; we cannot conclude the median difference of the times is greater than zero
D) do not reject the null hypothesis; we can conclude the median difference of the times is greater than zero

Question

A company that produces financial accounting software wants to offer better training to its customers. The training is intended to decrease the amount of time required to do complicated accounting calculations. For seven individuals, the amount of time (in minutes) to complete a complicated calculation is determined before and after completing the new training.  Using the critical value approach and α = 0.05, the appropriate conclusion is ________.
A) reject the null hypothesis; we cannot conclude the median difference of the times is greater than zero 
B) reject the null hypothesis; we can conclude the median difference of the times is greater than zero 
C) do not reject the null hypothesis; we cannot conclude the median difference of the times is greater than zero 
D) do not reject the null hypothesis; we can conclude the median difference of the times is greater than zero

Quizplus · Accepted Answer

We are testing whether the new training decreases the amount of time required to do complicated accounting calculations, which translates to testing for a difference in medians of the before and after times. Since the sample size is small (n=7) and the population distribution is unknown, we use the Wilcoxon signed-rank test.

Using the critical value approach and alpha = 0.05, we find the critical value to be 6. Since the test statistic (T-) is less than 6, we do not reject the null hypothesis. Therefore, we cannot conclude that the median difference of the times is greater than zero.

A Company That Produces Financial Accounting Software Wants to Offer