Exhibit 10

question 20

Multiple Choice

Exhibit 10.10.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. Refer to Exhibit 10.10.Assuming the difference D is normally distributed,what is the 95% confidence interval for μ_D?

• A)[-1.7537,5.7537]
• B)[-1.1459,5.1459]
• C)[-0.6739,4.6739]
• D)[-0.5368,4.5368]