Each student in a certain high school was classified according to her year in school (freshman, sophomore, junior, or senior) and according to the number of times that she had visited a certain museum (never, once, or more than once).The proportions of students in the various classifications are given in the following table:

a. If a student selected at random from the high school is a junior, what is the probability that she has never visited the museum?
b. If a student selected at random from the high school has visited the museum three times, what is the probability that she is a senior?

Transcribed Image Text:

More Freshmen Sophomores Juniors Seniors Neve Onc than once 0.08 0.04 0.04 0.02 0.10 0.04 0.04 0.09 0.10 0.10 0.15