The human height is the distance from head to toe When popul

The human height is the distance from head to toe. When populations share a genetic background and other environmental factors such as diet, the average height is frequently characteristic within a group. In a large group of Caucasians, how many individual must be measured to determine the mean height of a male within 5 inches at the 90% degree of freedom given the variance is 15 inches?

Solution

Given a=1-0.9=0.1, Z(0.05) = 1.645 (from standard normal table)

standard deviation =sqrt(15) =3.872983

So n=(Z*s/E)^2

=(1.645*3.872983/5)^2

=1.623615

Take n=2