Ask Question
22 November, 15:24

In a class of 100 students, 25 students have hardcover and 75 students have paperback textbooks for the course. If you randomly choose 10 students in this class, fnd the probability that 2 of them have hardcover texts in the following ways: a. the exact probability b. approximate probability using a binomial distribution

+3
Answers (1)
  1. 22 November, 18:33
    0
    h = prob of hardcover =.25

    p = prob of paperback =.75

    a.

    Prob (2 hardcover of 10) = (10 choose 2) (.25) ^2 (.75) ^8

    = (10 (9) / 2) (1/4^10) (1^2 3^8)

    = 295245/1048576

    ≈ 28.15%

    b.

    I think I just did the binomial distribution. We can approximate it as a normal distribution. The mean and variance in this case are computed thus:

    N=10, n=2

    μ = Np = 2.5

    σ² = Npq = 1.875

    σ = 1.3693

    P (n) = 1 / (σ√2π) e^ - (n-μ) / (2σ²)

    P (2) = 1 / (1.3693√2π) e^ - (2 - 2.5) / (2 (1.875))

    P (2) = 33.3%

    Pretty good, not great.
Know the Answer?
Not Sure About the Answer?
Get an answer to your question ✅ “In a class of 100 students, 25 students have hardcover and 75 students have paperback textbooks for the course. If you randomly choose 10 ...” in 📙 Mathematics if there is no answer or all answers are wrong, use a search bar and try to find the answer among similar questions.
Search for Other Answers