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

70 points ! pls 2. given the following two sets of data what is the union of the two sets and what is the intersection of the two sets. set a = {1, 2, 3, 4, 5, 6, 7, 8, 9} set b = {2, 4, 6, 8, 10, 12, 14} 3. given a regular deck of cards. describe a way of pulling cards that would create a dependent event and then one that would create an independent event. 4. what is the probability of drawing a red card and then drawing a spade without replacing the card that was drawn first?