CFA CFA Level 1 CFA Level 1 Question of the Week – Quantitative Methods

CFA Level 1 Question of the Week – Quantitative Methods

  • Author
    Posts
    • Avatar of Matt_AnalystPrepMatt_AnalystPrep
      Participant
        • CFA Charterholder
        Up
        6
        ::

        A trader purchases one single stock every day during five working days. His risk manager believes that the probability of selecting an underpriced stock at any given time is 52%. Assuming a binomial distribution, the probability of selecting exactly two underpriced stocks during the week out of the universe of underpriced and overpriced stocks is closest to:

        • A. 39.5%
        • B. 20.8%
        • C. 29.9%
      • Avatar of Lilynguyen_2195Lilynguyen_2195
        Participant
          • CFA Level 1
          Up
          4
          ::

          Who can explain this? Plz tell me

        • Avatar of Matt_AnalystPrepMatt_AnalystPrep
          Participant
            • CFA Charterholder
            Up
            2
            ::

            The correct answer is C.

            Since it’s a binomial distribution, we will solve the question with the help of the Bernoulli trial method. 

            The probability of having exactly 2 underpriced stocks in 5 trials (5 days), given that the probability of selecting an underpriced stock at any time is 52%, can be expressed as:

            (n!/x!*(n-x)!) * p^x * (1 – p)^(n-x)
            = 5!/(2!*3!) * 0.52^2 * (1 – 0.52)^3 
            = (120/12) * 0.2704 * (0.110592)
            = 0.2990

            where
            n is the number of trials;
            x is the number of days having purchased an underpriced stock; and
            p is the probability of selecting an underpriced stock.

        Viewing 2 reply threads
        • You must be logged in to reply to this topic.