Bernoulli trials
A Bernoulli trial is a random experiment with exactly two possible outcomes: success (usually \(1\)) and failure (usually \(0\)). The success probability is \(p\), and the failure probability is \(1-p\).
Binomial experiments
A binomial experiment satisfies both conditions:
Binomial random variables
A binomial random variable \(X\) counts the number of successes in \(n\) trials with success probability \(p\).
\[X\sim B(n,p),\qquad X\in\{0,1,2,\ldots,n\}\]
Binomial probability distribution function
\[P(X=x)=\binom nxp^x(1-p)^{n-x},\qquad x=0,1,2,\ldots,n\]
The binomial coefficient \(\binom nx\) counts the ways to choose the \(x\) successful trials from the \(n\) trials.
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