Suppose that we wish to test H0: = 20 versus Ha: < 20, where a

Question:

Suppose that we wish to test H0: μ = 20 versus Ha: μ < 20, where a is known to equal 7. Also, suppose that a sample of n = 49 measurements randomly selected from the population has a mean of = 18.
a. Calculate the value of the test statistic z.
b. By comparing z with a critical value, test H0 versus Ha at α = .01.
c. Calculate the p-value for testing H0 versus Ha.
d. Use the p-value to test H0 versus Ha at each of α = .10, .05, .01, and .001.
e. How much evidence is there that H0: μ = 20 is false and Ha: μ < 20 is true?