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OpenStax, Statistics §5.3 The Exponential Distribution (Optional) · Exercise 40 · Probability · Continuous distributions

The Exponential Distribution (Optional) · Exercise 40

According to the American Red Cross, about one out of nine people in the United States have type B blood. Suppose the blood types of people arriving at a blood drive are independent. In this case, the number of type B blood types that arrive roughly follows the Poisson distribution.

(a) If 100 people arrive, how many on average would be expected to have type B blood?
(b) What is the probability that more than 10 people out of these 100 have type B blood?
(c) What is the probability that more than 20 people arrive before a person with type B blood is found?

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OpenStax, Statistics · §5.3 The Exponential Distribution (Optional) · Exercise 40

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