A bank is trying to determine which model of safe to install. The bank manager believes that each model is equally resistant to safe crackers but sets up a test to be sure. He hires nine safe experts to break into each of the models, timing each endeavor. The results (in seconds) are given next, paired by expert. Let D be the difference: Time to break Safe 1 minus Time to break Safe 2. Safe 1 Safe 2 103 101 90 94 64 58 120 112 104 103 92 90 145 140 106 110 76 74 Should we conclude that the average time it takes experts to crack the safes does not differ by model at the 5% significance level?