Mean
A measure of the average value
1. of a sample
Given a sample of \(n\) values \(x_i\), the mean is defined as
2. of a distribution
For a random variable \(X\) with the distribution in question, the mean is equal to the expectation of the function
1. of a sample
Given a sample of \(n\) values \(x_i\), the mean is defined as
\[
\frac{1}{n}\sum_{i=1}^{n}x_i
\]
where \(\sum\) is the summation sign.2. of a distribution
For a random variable \(X\) with the distribution in question, the mean is equal to the expectation of the function
\[
f(X) = X
\]