Question

A study shows that length of the careers of professional basketball players are nearly normally distributed, with a mean of 6.1 years and a standard deviation of 1.8 years. If there are 250 players, how many have a career of less than 5 years?

Answer 1

$z=\frac{x-\mu}{\sigma}=\frac{5-6.1}{1.8}=-0.61$

$P(z<-0.61)=0.2709$

number of students who have a career of less than 5 years:

$n=0.2709\cdot250=67.725\approx 68$ students