8.113 Ice Hockey II Exercise 8.112 presented sta- tistics from a study of fast starts by ice hockey skaters. The mean and standard deviation of the 69 individual average acceleration measurements over the 6 m dis- tance were 2.962 and 0.529 metres per second (m/sec), respectively.

a. Find a 95% confidence interval for this population mean. Interpret the interval.

b. Suppose you were dissatisfied with the width of this confidence interval and wanted to cut the interval in half by increasing the sample size. How many skat- ers (total) would have to be included in the study?