1. 5 pregnant women
5 pregnant women are sitting around a table.
A (20pts). What is the probability that all of them will have boys?
What is the probability that one will have a girl, while the rest have boys?
2. UofM graduation rates
By looking at statistics for UofM freshman enrollment by ethnicity, you know that the probability of a freshman being black is 0.08 (8%), asian is 0.13, hispanic is 0.06, and white/other is 0.73. You also know that the 4-year graduation rates for those groups are 0.51 (black), 0.76 (asian), 0.67 (hispanic), and 0.75 (white/other).
A (20 pts). Draw a probability tree with the first branching corresponding to ethnicity, and the second corresponding to whether the student graduated in four years or not.
B (20 pts).
What is the probability that a student does not graduate in 4 years?
C (20 pts). What is the probability that
a student who graduated in 4 years is black? That is, given that he/she graduated in 4 years, what is the probability that he/she is black?