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An insurance company classifies its policyholders into three tiers – standard, preferred, and ultra preferred. 40% of standard tier policyholders are male, 50% of preferred tier policyholders are male and 75% of ultra preferred tier policyholders are male. There is an equal number of policyholders in each tier. If a policyholder is selected at random, what is the chance she is female?
Explanation:
This is a probability problem using the law of total probability. Let's define the events:
Given information:
Applying the law of total probability:
P(F) = P(F|S) × P(S) + P(F|P) × P(P) + P(F|U) × P(U)
P(F) = 0.60 × (1/3) + 0.50 × (1/3) + 0.25 × (1/3)
P(F) = (0.60 + 0.50 + 0.25) × (1/3)
P(F) = 1.35 × (1/3)
P(F) = 0.45 or 45%
Verification:
The correct answer is 45%, which corresponds to option D.