Construct a 95% confidence interval estimate for the difference in wait times for ITM and Dull computers, based on the data in Exercise 16 above. Do you expect this interval to contain zero? Why or why not?
In exercise
A large college was considering switching brands of the laptop computers they lease for faculty. To test the quality of the support available, IT workers made a number of calls throughout one week to the support lines for each manufacturer. The workers recorded the number of minutes that they waited on the phone before a technician became available. The average wait time for the ITM brand was 8.5 minutes, with a standard deviation of 2.6 minutes, with a sample size of 34.