According to Moebs Services Inc., the average cost of an individual checking account to major U.S. banks was $380 in 2013 (www.moebs.com). A bank consultant wants to determine whether the current mean cost of such checking accounts at major U.S. banks is more than $380 a year. A recent random sample of 150 such checking accounts taken from major U.S. banks produced a mean annual cost to
them of $390. Assume that the standard deviation of annual costs to major banks of all such checking accounts is $60.
a. Find the p-value for this test of hypothesis. Based on this p-value, would you reject the null hypothesis if the maximum probability of Type I error is to be .05? What if the maximum probability of Type I error is to be .01?
b. Test the hypothesis of part a using the critical-value approach and α = .05. Would you reject the null hypothesis? What if α = .01? What if α = 0?