In 2001, the probability of a college student being male was 0.44. For males, the probability of being a part-time student was 0.38. For females, the probability of being a part-time student was 0.43.
a. To the nearest hundredth, find the probability of a college student in 2001 being part-time.
b. Which is taken to be the explanatory variable here-gender or type of student?