Question

Men heights are assumed to be normally distributed with mean 70 inches and standard deviation 4 inches; what is the probability that 4 randomly selected men have an average height less than 72 inches?

Answer 1

Solution :

Given that ,

mean = = 70 inches

standard deviation = = 4 inches

n = 4

=    = 70 inches

= / n = 4 / 4 = 2 inches

P( < 72) = P(( - ) / < (72 - 70) / 2)

= P(z < 1.00)

Using z table

= 0.8413