Police recorded the average speed of cars driving on a busy street by a school. For a sample of 49

speeds, it was determined that the average amount over the speed limit for the 49 speeds was 17.3 mph with a standard deviation of 10 mph. The 95% confidence interval estimate for this sample is 14.43 mph to 20.17 mph.

b) What size sample is needed to reduce the margin of error to no more than 2?

Please show all steps as to how you solved for n.