In Exercise 9 we considered the relationship between grade-point average (GPA) and weekly hours spent in the campus pub. Suppose that a freshman economics student has been spending 15 hours a week in the Orange and Brew during the first two weeks of class. Calculate a 90% confidence interval for his GPA in his first quarter of college if he continues to spend 15 hours per week in the Orange and Brew. Suppose that this freshman remains in school for four years and completes the required 12 quarters for graduation. Calculate a 90% confidence interval for his final cumulative GPA. Suppose that the minimum requirements for acceptance into most graduate schools for economics is 3.25. What are the chances that this student will be able to go to graduate school after completing his undergraduate studies?