Question

The population standard deviation for the height of college basketball players is 3.5 inches. If we want to estimate 90% confidence interval for the population mean height of these players with a 0.9 margin of error, how many randomly selected players must be surveyed? (Round up your answer to nearest whole number)

Answer 1

z critical for 90% is 1.645 [From z table]

Margin of error E = 0.90

Standard deviation sd = 3.5

sample size n = ((z*sd)/E)^2

=((1.645*3.5)/0.9)^2

= 6.3972^2

= 40.92

= 41

Sample size n = 41 (rounded)