Suppose you are working for a regional residential natural gas utility. For a sample of 85 customer visits, the staff time per reported gas leak has a mean of 231 minutes and standard deviation 35 minutes. The VP of network maintenance hypothesizes that the average staff time devoted to reported gas leaks is 237 minutes. At a 1 percent level of significance, what is the lower bound of the interval for determining whether to accept or reject the VP's hypothesis