Practice Questions 1.David ran a marathona few years ago.

Practice Questions

1. David ran a marathon a few years ago. Given that the mean finishing time for all runners was 254 minutes with a standard deviation of 43 minutes and that finishing times were approximately normally distributed, find

(a) the percent of finishers who ran faster than Prof. Miller's time of 3 hr 30 min.

(b) a time that was the 65th percentile (65% of finishers were under that time)

(c) the percent to runners who finished between 3 hours and 4 hours

(d) Suppose there just happened to be 11 other runners with the same last as me (so 12 Millers!) What is the probability that the mean of the 12 Millers' times is more than 240 minutes?