1.In a recent Des Moines marathon, 36% of the racers were female.The distribution of finishing times for the female runners was normally distributed with a mean of 280 minutes and a standard deviation of 45 minutes.For male runners, their finishing times were also normally distributed with a mean of 262 minutes and a standard deviation of 40 minutes.

a.The fastest 33% female runners finished the race in under what time?

b.What proportion of male runners finished between 4 and 5 hours?

c. Of those that finished under 4 hours, what proportion were female?