This is an practice question I am working on can you help me so I may compare my results, thank you?

This is an practice question I am working on can you help me so I may compare my results, thank you?

A professor has been teaching statistics for many years. His records show that the overall mean for final exam scores is 85 with a standard deviation of 10. He believes that this year's class is superb to the previous classes. The mean for the 40 students is 90.

a.    What is the null hypothesis?

b.    What is the research hypothesis?

c.    Is this a one or two tailed hypothesis?

d.    Which test should you use? Why?

e.    Calculate the appropriate statistical test.

f.     What is the critical value for α = .05?

g.    What do you conclude?