Historically, the average waiting time spent on hold when phoning customer service for a particular bank was one and a half minutes. To determine whether the average time people were waiting had changed since they cut the number of customer service staff, the bank undertook a random sample of the waiting time recorded by 15 customers. The results are in the Y column (in seconds) of the data file P14.12.xls which can be found in a folder under the CML Quizzes tab.
Assume that the test is performed at the 5% level of significance and that the distribution of waiting times is approximately normally distributed.
1.State the direction of the alternative hypothesis used to test whether average waiting time had changed. Type gt (greater than), ge (greater than or equal to), lt (less than), le (less than or equal to) or ne (not equal to) as appropriate in the box.