What is the 40th percentile of a normal distribution with mean = 5 and variance = 9? 

The study is expanded to include 50 medical interns, of whom 11 report having had an automobile accident over the past year.

One issue in the above study is that not all people report automobile accidents to the police. The NHTSA estimates that only half of all auto accidents are actually reported. Assume this rate applies to interns.