Suppose that you are testing the hypotheses H0: = 16 vs. HA: < 16. A

Question:

Suppose that you are testing the hypotheses H0: μ = 16 vs. HA: μ < 16. A sample of size 25 results in a sample mean of 16.5 and a standard deviation of 2.0.
a) What is the standard error of the mean?
b) What is the critical value of t* for a 90% confidence interval?
c) Construct a 90% confidence interval for m.
d) Based on the confidence interval, at α = 0.05 can you reject H0? Explain.