Question

The mean height of women in a country? (ages 20minus?29) is 64.4 inches. A random sample of 55 women in this age group is selected. What is the probability that the mean height for the sample is greater than 65 ?inches? Assume sigmaequals2.54. The probability that the mean height for the sample is greater than 65 inches is

Answer 1

Solution:

Given that,

= 64.4

= 2.54

n = 55

So,

= 64.4

=  ( /n) = (2.54 / 55 ) = 0.3425

p (   > 65 )

= 1 - p (   < 65 )

= 1 - p ( -  /   ) < ( 65 - 64.4 / 0.3425 )

= 1 - p ( z < 0.6 /0.3425 )

= 1 - p ( z < 1.75)

Using z table

= 1 - 0.9599

= 0.0401

Probability = 0.0401