WEBVTT

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Here is the problem: X is binomial with n equals 6 and p equals 0.5. Find P(X equals 3).

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Binomial: k successes in n trials.

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Binomial probability of exactly j successes.

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Substitute j equals 3.

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Mean and standard deviation of the distribution.

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So the answer is P(X equals 3) approximately 0.3125 (31.25 percent).

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With 6 independent trials and success probability 1 over 2 per trial, the requested probability is about 31.25 percent.

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All binomial probabilities for j equals 0..6 add to 1.