It is estimated that heights of adult men are normally distributed with a mean of 70 inches and a standard deviation of 3.5. In one state, the law requires a person to be 68 inches or taller to become a fire fighter.

Question

(a) What proportion of adult men will meet this height requirement for becoming a fire fighter in this state?
(b) A person who was denied to become a fire fighter learned that his height was at the 20th percentile. What was his actual height?

Answer 1

a. Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score.

b. Use same table to find Z and insert into equation above to solve.