need help with the following sw

Studies show that massage therapy has a variety of health benets and it is not too expensive. A sample of 12 typical one-hour massage therapy sessions showed an average charge of $52. The population standard deviation for a one-hour session is a = $5.5. (a) What assumptions about the population should we be willing to make if a margin of error is desired? 0 We should be willing to make the assumption that the population is at least approximately uniform. 0 We should be willing to make the assumption that the population is at least approximately bimodal. 0 We should be willing to make the assumption that the population is at least approximately skewed right. 0 We should be willing to make the assumption that the population is at least approximately normal. 0 We should be willing to make the assumption that the population is at least approximately skewed left. (b) Using 95% condence, what is the margin of error in dollars? (Round your answer to the nearest cent.) $ (c) Using 99% condence, what is the margin of error in dollars? (Round your answer to the nearest cent.) $