Look at Figure 4-11, “Who’s Cracking the Books?”

(a) Does the figure show the probability distribution of grade records for male students? for female students? Describe all the grade-record probability distributions shown in Figure 4-11. Find the probability that a male student selected at random has a grade record showing mostly A’s.(b) Is the probability distribution shown for all students making mostly A’s? Explain your answer.
(c) Can we use the information shown in the figure to determine the probability that a graduating senior has grades consisting of mostly B’s or higher? What is the probability?
(d) Does Figure 4-11 give sufficient information to determine the probability that a student selected at random is in the age range 19 to 23 and has grades that are mostly B’s? What is the probability that a student selected at random has grades that are mostly B’s, given he or she is in the age range 19 to 23?
(e) Suppose that 65% of the students at State University are between 19 and 23 years of age. What is the probability that a student selected at random is in this age range and has grades that are mostly B’s?

Undergraduate Grade Record by Student Characteristic C's and D's A's and B's and C's or lower Student characteristic Gender: Men Women Class level: Graduating senior All other class levels Age: 18 or younger 19 to 23 24 to 29 30 to 39 40 and older Source: U.S. Department of Education 38.8% 29.4 15.8 % 35.4 42.6% 38.1 33.3 23.1 20.1 16.6 % 16.2 21.9 % 15.8 14.7% 19.0 16.9 13.2 10.1 Mostly B's 22.6 % 26.2 34.5 % 23.6 23.4 % 25.1 24.7 25.9 22.0 B's 9.6% 12.0 14.7% 10.5 9.4% 9.4 10.3 14.8 14.8 Mostly A's 12.4% 16.2 13.0 % 14.7 10.0 % 8.3 14.9 23.0 33.0