suppose-you-are-told-that-a-95-confidence-interval-for-the-average-price-of-a-gallon-of-regular-gasoline-in-your-state-is-from-3-07-to-3-81-use-the-fact-that-the-confidence-interval-for-the-mean-is/

Suppose you are told that a 95% confidence interval for the average price of a gallon of regular gasoline in your state is from $3.07 to $3.81. Use the fact that the confidence interval for the mean is in the form x − E to x + E to compute the sample mean and the maximal margin of error E.