Suppose That at a Certain School, All 1500 Students Write

Short Answer

Suppose that at a certain school, all 1500 students write letters to pen pals. The number of letters each student sends is independent of the number of letters other students send. Furthermore, the numbers of letters written by students are identically distributed random variables with mean 8 and standard deviation 2.2. Find the 90th percentile of the numbers of letters written.