John Beale of Stanford, CA, recorded the speeds of cars driving past his house, where the speed limit read 20 mph. The mean of 100 readings was 23.84 mph. with a standard deviation of 3.56 mph. (He actually recorded every car
for a two-
month period. These are 100 representative readings.)
If the distribution follows a Normal model where speeding over 20.28 miles per hour?