Suppose that a forester wants to see if the average height of lodgepole pines in Yellowstone is different from the national average of 70 ft. The standard deviation lodgepole pine height is known to be 9.0 ft. The forester decides to measure the height of 19 trees in Yellowstone and use a one-sample z-test with a significance level of 0.01. She constructs the following null and alternative hypotheses, where mu is the mean height of lodgepole pines in Yellowstone.
H_0: mu = 70
H_1: mu notequalto 70
Use software to determine the power of the hypothesis test if the true mean height of lodgepole pines in Yellowstone is 62 ft. You may find one of these software manuals useful. Write your answer in decimal form and round to three decimal places.
Power =

Make sure it is set to Stats, then for mu0, do 70; for standard deviation, do 9; for mean, you do 62; for sample size, you do 19. For mu, you do not equal to mu0. Then you hit "Calculate".

You then get a z-value (critical value) of -3.874576839, and a p-value of 0.00010685098.

This means that...

We reject the null hypothesis that the average height of lodgepole pines in Yellowstone is 70 feet because p = 0.0001 is less than the significance level of alpha = 0.01. There is sufficient evidence to suggest that the mean height of lodgepole pines in Yellowstone is NOT equal to 70 feet.

Hope this helps!