WEBVTT

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Here is the problem: X is binomial with n equals 20 and p equals 0.1. Find P(X less than 2).

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Binomial: k successes in n trials.

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Binomial probability of exactly j successes.

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Add the terms for j equals 0 to 1.

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Mean and standard deviation of the distribution.

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So the answer is P(X less than 2) approximately 0.3917469981 (39.1747 percent).

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With 20 independent trials and success probability 1 over 10 per trial, the requested probability is about 39.1747 percent.

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All binomial probabilities for j equals 0..20 add to 1.