In 1988, the probability of a college student being part-time was 0.43. For part-time students, the probability of being male was 0.39. For full-time students, the probability of being male was 0.49.
a. To the nearest hundredth, find the probability of a college student in 1988 being male.
b. Which is taken to be the explanatory variable here-gender or type of student?