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OpenStax, Statistics §4.4 Geometric Distribution (Optional) · Exercise 13 · Probability · Discrete distributions

Geometric Distribution (Optional) · Exercise 13

Researchers investigate the prevalence of a particular infectious disease in countries around the world. According to their data, “Prevalence of this disease refers to the percentage of people ages 15 to 49 who are infected with it.” In South Africa, the prevalence of this disease is 17.3 percent. Let X = the number of people you test until you find a person infected with this disease.

(a) Sketch a graph of the distribution of the discrete random variable X.
(b) What is the probability that you must test 30 people to find one with this disease?
(c) What is the probability that you must ask 10 people?
(d) Find the (i) mean and (ii) standard deviation of the distribution of X.

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OpenStax, Statistics · §4.4 Geometric Distribution (Optional) · Exercise 13

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