Calculate the sample size required to test the hypothesis th

Calculate the sample size required to test the hypothesis that u = 5.4 against the alternative hypothesis u < 5.48 if the power of the test is to be .90 when the true mean is 5.25? assume that SD = .22

Solution

POWER = 0.90 = 1 - BETHA =

BETHA = 0.10

Z= 1.64

n = 1.64^2 * 5.25    /   0.22

n = 64.18

n = 65

sample size = 65