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

Which of the following hypotheses will determine if the two safes take, on average, the same amount of time to crack?

Multiple Choice

H₀: _D 0, H_A: _D <0

H₀: _D 0, H_A: _D >0

H₀: _D = 0, H_A: _D 0

H₀: _D 0, H_A: _D =0