Question

The population standard deviation for the height of college baseball players is 3.2 inches. If we want to estimate 90% confidence interval for the population mean height of these players with a 0.7 margin of error, how many randomly selected players must be surveyed? (Round up your answer to nearest whole number)

Answer 1

Solution :

Given that,

standard deviation =   =3.2

Margin of error = E = 0.7

At 90% confidence level

= 1 - 90%  

= 1 - 0.90 =0.10

/2 = 0.05

Z/2 = Z _{0.05 = 1.645}

sample size = n = [Z/2 * / E] ²

n = ( 1.645 * 3.2 /0.7 )²

n =56.5504

Sample size = n =57