SOLUTION: Statistics shows that only 40 % of South African women are overweight. Consider a randomly selected group of twenty South African women. Calculate the probability that: 4.1.1. thr

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Question 1045645: Statistics shows that only 40 % of South African women are overweight. Consider a randomly selected group of twenty South African women. Calculate the probability that:
4.1.1. three are overweight.
4.1.2. none is overweight
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
probability 3 are overweight is 20C3(0.4)^3(0.6)^17=0.0123. This is low, but the expected value is 8, (and the probability of 8 is 0.1797, much higher, so this makes sense).
For none, the probability is 0.6^20=3.66 x 10^(-5)