The average daily volume of certain Computer stock in 2011 was 42.8 million shares, with standard deviation of sigma= 16.4 million shares according to reputable financial journal. An analyst claims that the stock volume in 2012 is different from that of year 2011. Based upon a random sample of 35 trading days in 2012, he finds out a sample mean of 39.2 million shares. Test the analyst's claim at alpha = .10 level of significance. Suppose that sigma remains 16.4 million shares.
a. Describe the null and the alternate hypotheses. Ho: ___and Ha: ___
b. Describe the critical value(s) for this test. _____
c. Determine the test statistic. _____
d. Determine the p-value for this test. ____
e. Explain your conclusion in the context of this problem. ______