Q1 What critical value for z would be used to test the hypot

Q1: What critical value for z would be used to test the hypothesis:

H₀: µ15 versus

H_a: µ<15, for a = 0.01

Solution

There are 2 important factor which determine the critcal value of z.

First whether it is a one sided or two sided test. In this case we clearly have a one sided test. Now the second factor is the alpha which is 0.01. The value of z for which the probability in z-table is given to be 0.01 will be the critical value.

Critical z = z_0.01 = -2.326