Suppose you are working for a regional residential natural gas utility. For a sample of 90 customer visits, the staff time per reported gas leak has a mean of 211 minutes and standard deviation 31 minutes. The VP of network maintenance hypothesizes that the average staff time devoted to reported gas leaks is 219 minutes. At a 10 percent level of significance, what is the lower bound of the interval for determining whether to accept or reject the VP's hypothesis