Question

Historically, the average height of females in the freshman class of a certain college has been 162.5 centimeters. Is there reason to believe that there has been a change in the average height if a random sample of 50 females in the present freshman class has an average height of 165.2 centimeters, with a standard deviation of 6.9 centimeters? Assume the level of significance equals 0.05 and that height is normally distributed. What is/are the critical value(s) for this hypothesis test?

t = -2.01 and 2.01
		z = 1.96
		z = -1.96 and 1.96
		z = -1.645 and 1.645

Answer 1

Solution:

This is a two tailed test,

Critical value of  the significance level is α = 0.05, and the critical value for a two-tailed test is

z = -1.96 and 1.96