4. The two-way table below describes the results of a sample of 100 random middle school students and their ice cream preferences.

Ice Cream Preferences Likes Strawberry Doesn't Like Strawberry Total

Likes Chocolate 30 40 70

Doesn't Like Chocolate 10 20 30

Total 40 60 100

(a) Find the probability that a randomly selected middle school student likes chocolate or strawberry ice cream.

(b) Find the probability that a middle school student likes chocolate ice cream and not strawberry ice cream.

(c) What's the probability that a randomly selected middle school student likes chocolate ice cream, given that they like strawberry ice cream?

5. A census of students at a very large high school was taken and each was asked their grade level and in which location they ate lunch every day during one of the three lunch periods. The results are summarized below. Suppose we choose a student at random from these 2640 students.

Large Cafe Small Cafe Student Center Total

Freshman 110 435 80 625

Sophomore 250 275 125 650

Junior 375 150 110 635

Senior 350 0 280 635

Total 1085 860 595 2640

(a) Find P(Junior).

(b) Find P(Senior and Large Cafeteria).

(c) Find P(Sophomore or Student Center).

(d) Find P(Freshman | Small Cafeteria).

Given they eat in the small cafeteria, probability of a freshman