Question

For a certain class, the following data table summarizes the amount of sleep of students and whether or not they have an A in the class. What is the probability that a student chosen randomly from the class slept 6 hours or less?
Slept more than 6 hours Slept 6 hours or less
Has an A 2 4
Does not have an A 3 17

Answer 1

Number who slept 6 hours or less = 4 + 17 = 21.
Total students = 2 + 4 + 3 + 17 = 26.
Probability = 21/26 ≈ 0.8077 ≈ 80.8%.