Question

The following table shows information collected from a survey of students regarding their grade level and transportation they use to arrive at school. What is the probability that a randomly selected eighth grader takes the bus?

Answer 1

Answer: 0.25

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Work Shown:

A = student selected is an eighth grader
B = chosen student takes bus
P(A) = probability of selecting eighth grader
P(A and B) = probability of selecting eighth grader AND student who takes bus
P(A and B) = probability of selecting eighth grader who takes the bus
P(B|A) = probability of selecting someone who takes the bus given they are an eighth grader

P(B|A) = [P(A and B)]/[P(A)]
P(B|A) = 0.11/0.44
P(B|A) = 0.25