申論題

4. (總分 40 分) A statistics instructor is interested in applying a simple regression to test whether students' performance in the midterm exam (x, midterm exam scores) is associated with their performance in the final exam (y, final exam scores). The model to be estimated is , and the data is as follows:
 

(b). (10 分) What is the sampling distribution of ? (Hint: probability distribution, mean, and standard error)