A friend of mine believes that the average GPA at KSU is equal to 3.0. In order to test whether he/she is right, I collect some information from the data. Specifically, I use 100 KSU students to form a sample and find that their sample average GPA is equal to 3.2. In addition, suppose that I also know the population standard deviation of GPA at KSU is 1.0. I decide to use 0.05 as the level of significance for my hypothesis testing.

1 What should be my null hypothesis? What should be my alternative hypothesis?

2 Is this a lower-tailed, upper-tailed or two-tailed case?

3 Show me how to calculate my test statistic.

4 If I use the critical value approach, explain how to derive my critical value(s).