Consider the following hypothesis test.

H₀:10

H_a:< 10

The sample size is120and the population standard deviation is assumed known with= 5.

Use= 0.05.

(a)

If the population mean is 9, what is the probability that the sample mean leads to the conclusiondo not rejectH₀?

(Round your answer to four decimal places.)

(b)

What type of error would be made if the actual population mean is 9 and we conclude thatH₀:10

is true?

Type I

Type II

(c)

What is the probability of making a type II error if the actual population mean is 8? (Round your answer to four decimal places. If it is not possible to commit a type II error enter NOT POSSIBLE.)