statistics and probability

3. A large gas station chain reports that the amount of gasoline purchased per visit, r. is normally distributed with standard deviation o = 2 gallons. Suppose that a random sample of 25 purchases at this station is selected. The sample average is 12.4 gallons. (a) Explain why we can assume that the distribution of I is approximately normal. (b) Compute a 95% confidence interval for . Round to three places. (c) What is the margin of error for the interval estimate? Round to three places. (d) An executive from this gas station chain claims that, on average, customers purchase 15 gallons of gas per visit. Is this claim supported by the data? In a sentence, explain why or why not