What to know
Identify the rule, formula, or decision criterion before reading the answer choices. CFA Level I distractors often use the right vocabulary with the wrong condition.
Probability Trees and Conditional Expectations is part of CFA Level I Quantitative Methods. Quantitative Methods questions emphasize time value of money, probability, sampling, hypothesis testing, regression, and return statistics. Use this page to review the controlling ideas, then work through 8 questions with answer explanations and common traps.
Review the worked explanations before moving into adaptive practice. The app version can mix this topic with due reviews and weak related concepts.
Practice this topicIdentify the rule, formula, or decision criterion before reading the answer choices. CFA Level I distractors often use the right vocabulary with the wrong condition.
Work each item under time pressure, then compare your reasoning with the step-by-step explanation and key takeaway.
Missed questions should become scheduled reviews when the error comes from a concept gap, formula setup, or answer-choice trap.
Probability Trees and Conditional Expectations
An asset has returns of -10%, 5%, and 15% with probabilities 20%, 50%, and 30%. The expected return is closest to:
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If P(A and B) = 0.18 and P(B) = 0.30, P(A | B) is closest to:
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A model assigns a 60% probability to expansion. If expansion occurs, the probability of a positive earnings surprise is 80%; if recession occurs, it is 30%. The unconditional probability of a positive surprise is closest to:
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If the economy expands, a stock is expected to return 12%; if it contracts, it is expected to return -6%. Given a 70% probability of expansion, the expected return is closest to:
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For returns of -10%, 5%, and 15% with probabilities 20%, 50%, and 30%, the standard deviation is closest to:
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Thirty percent of analysts are skilled. A favorable signal occurs 80% of the time for a skilled analyst and 25% of the time for an unskilled analyst. Given a favorable signal, the probability the analyst is skilled is closest to:
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A strategy loses 4 if a signal is wrong and gains 6 if the signal is correct. The signal is correct with probability 65%. The expected payoff is closest to:
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A risk report gives P(Default | Downgrade) = 18% and P(Downgrade | Default) = 60%. The analyst uses 60% as the probability of default after a downgrade. The analyst most likely confused:
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