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OpenStax, Statistics §4.4 Geometric Distribution (Optional) · Exercise 7 · Probability · Discrete distributions

Geometric Distribution (Optional) · Exercise 7

A consumer looking to buy a used red sports car will call dealerships until she finds a dealership that carries the car. She estimates the probability that any independent dealership will have the car will be 28 percent. We are interested in the number of dealerships she must call.

(a) In words, define the random variable X.
(b) List the values that X may take on.
(c) Give the distribution of X. X ~ _____(_____,_____)
(d) On average, how many dealerships would we expect her to have to call until she finds one that has the car?
(e) Find the probability that she must call at most four dealerships.
(f) Find the probability that she must call three or four dealerships.

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OpenStax, Statistics · §4.4 Geometric Distribution (Optional) · Exercise 7

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