The mean and standard deviation of the speeds of the sample of 69 skaters at the end of the 6-meter distance in Exercise 8.108 were 5.753 and .892 meters per second, respectively.
a. Find a 95% confidence interval for the mean velocity at the 6-meter mark. Interpret the interval.
b. Suppose you wanted to repeat the experiment and you wanted to estimate this mean velocity correct to within .1 second, with probability .99. How many skaters would have to be included in your sample?