I have noted from past experience that a student who has done all assignments has a probability of 0.8 of getting 8- or better, While a student who has missed some assignments has a probability of 0.2 of getting 8 or better. I expect that 70% of students Will do all the assignments this semester. Based on those probabilities, What is the probability that a student gets 8- or better this semester. a. 65% b. 67.5% c. 69% d. 62% e. 68%