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OpenStax, Introductory Statistics 2e §4.6 Poisson Distribution · Try It 5 · Probability · Discrete distributions

Poisson Distribution · Try It 5

According to a recent poll by the Pew Internet Project, people between the ages of 14 and 17 send an average of 187 text messages each day. Let X = the number of texts that a girl aged 14 to 17 sends per day. The discrete random variable X takes on the values x = 0, 1, 2 …. The random variable X has a Poisson distribution: X ~ P(187). The mean is 187 text messages.

(a) What is the probability that a person sends exactly 175 texts per day?
(b) What is the probability that a person sends at most 150 texts per day?
(c) What is the standard deviation?

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OpenStax, Introductory Statistics 2e · §4.6 Poisson Distribution · Try It 5

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