Thunderstorm Speeds A meteorologist who sampled 13 thunderstorms found that the average speed at which they traveled across a certain state was 17 miles per hour. The standard deviation of the sample was 1.6 miles per hour. Use a graphing calculator and round the answers to at least one decimal place. Part: 0/2 Part 1 of 2 Find the 97% confidence interval of the mean. Assume the variable is normally distributed.