A recent report suggests that business majors spend the least amount of time on course work than all other college students (The New York Times, November 17, 2011). A provost of a university decides to conduct a survey where students are asked if they study hard, defined by spending at least 20 hours per week on course work. Of 120 business majors included in the survey, 20 said that they studied hard as compared to 48 out of 150 non-business majors who said that they studied hard.
a. Construct a contingency table that shows the frequencies for the qualitative variables Major (business or non-business) and Study Hard (yes or no).
b. Find the probability that a business major spends less than 20 hours per week on course work.
c. What is the probability that a student studies hard?
d. If a student spends at least 20 hours on course work, what is the probability that he/she is a business major?
What is the corresponding probability that he/she is a non-business major?