Phone Solutions provides assistance to users of a personal finance software package. Users of the software call with their questions, and trained consultants provide answers and information. One concern that Phone Solutions must deal with is the staffing of its call centers. As part of the staffing issue, it seeks to reduce the average variability in the time each consultant spends with each caller. A study of this issue is currently under way at the company's three call centers. Each call center manager has randomly sampled 50 days of calls, and the collected times, in minutes, are in the file Phone Solutions.
a. Call Center 1 has set the goal that the variation in phone calls, measured by the standard deviation of length of calls in minutes, should be less than 3.5 minutes. Using the data in the file, can the operations manager of Call Center 1 conclude her consultants are meeting the goal? Use a 0.10 level of significance.
b. Can the manager conclude there is greater variability in the average length of phone calls for Call Center 3 than for Call Center 2? Again, use a 0.10 level of significance to conduct the appropriate test.