Answer
a. It didn't change.
b. The variation lowered.
c. Satisfaction increased
d. The single line is preferable.
Work Step by Step
a. From the data, we see that the mean waiting time did not change, for the means of the two data sets are not different.
b. The problem states that the standard deviation changed from 1.8 to .5, so it follows that the deviation lowered.
c. Satisfaction increased, for the waiting time was more consistent. After all, even if the average does not change, people are more satisfied when the time it takes is more consistent.
d. The single line is preferable, for it improves customer satisfaction.
