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Binomial, Poisson, and Multinomial Distributions

  1. A binomial distribution has only two possible outcomes. You can think of them as successes and failures. For the correct answers, the successes are: a flip of heads, a win for Susan, a group member who has passed the midterm, and a correct answer on a multiple-choice question.

  2. You may use the Binomial Calculator (n = 10, p = .5, > or = 8). Otherwise add up the probability of getting 8, 9, and 10 heads: .044 + .01 + .001 = .055

  3. Use the Binomial Calculator (n = 20, p = .3, > or = 8). p = .23

  4. Use the Binomial Calculator (n = 20, p = .3, less than or = 3). p = .11

  5. M = np = 20 \times .3 = 6

  6. Var = np(1-p) = 50(.6)(1-.6) = 12