A researcher hypothesizes that University of Miami students are more likely to report higher job satisfaction after they graduate compared to other schools. She uses a 1 to 100 scale, with 1 being the lowest and 100 being the highest job satisfaction. A sample of 100 UM graduates report their average job satisfaction is 89. She compares this group to the U. S. national average for university graduates. The national average job satisfaction is 84, with a standard deviation of 16. Required:
a. Should the test be one- or two-tailed?
b. What statistical test should the researcher use?
c. What is the null hypothesis?