1. State the four basic assumptions about the general form of the probability distribution of the random error 8 in the linear regression model. (8 %)

4. A random sample of 250 students at a university finds that these students take a mean of 14.7 credit hours per quarter with a standard deviation of 2.2 credit hours. Find the 95% confidence interval for the mean credit hours taken by a student each quarter. (12 %)