Suppose that you are testing the hypotheses H0=μ=18 vs. HA:μ<18. . sample of size 16 results in a sample mean of 18.5 and a sample standard devation of 1.6 a) What is the standard orror of the mean? b) What is the critical value of t" for a 95% confidence interval? c) Construct a 95% confidence interval for μ. d) Based on the confidence interval, at α=0.025 can you reject H0 ? Explain.