Question

find the indicated probabilities using the geometric distribution, the poisson distribution, or the binomial distribution. then determine if the events are unusual. if convenient, use the appropriate probability table or technology to find the probabilities.

assume the probability that you will make a sale on any given telephone call is 0.13. find the probability that you (a) make your first sale on the fifth call, (b) make your first sale on the first, second, or third call, and (c) do not make a sale on the first three calls.

(a) p(make your first sale on the fifth call) = 0.074
(round to three decimal places as needed.)

(b) p(make your first sale on the first, second, or third call) = 0.341
(round to three decimal places as needed.)

(c) p(do not make a sale on the first three calls) = 0.659
(round to three decimal places as needed.)

which of the events are unusual? select all that apply.

a. the event in part (a), \make your first sale on the fifth call\, is unusual.
b. the event in part (b), \make your first sale on the first, second, or third call\, is unusual.
c. the event in part (c), \do not make a sale on the first three calls\, is unusual.
d. none of the events are unusual.

Explanation:

Identify the probabilities of the events

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$$

Define the threshold for an unusual event

$$ \text{An event is considered unusual if its probability is less than or equal to } 0.05. $$

Compare probabilities to the threshold

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$$

Answer:

• A. The event in part (a), "make your first sale on the fifth call", is unusual.
• B. The event in part (b), "make your first sale on the first, second, or third call", is unusual.
• C. The event in part (c), "do not make a sale on the first three calls", is unusual.
• D. None of the events are unusual. (Correct answer)