What is the mathematical symbol for average?

Answer 1

The mathematical symbol for average is sometimes denoted by putting a line above the variable, like this:

_

X

The "Expectation value" of a random variable - is like a weighted average. E[X] or <X> or the Greek letter mu (µ) - are a few of the common symbols for the Expected Value of X.

A random variable may, for example, represent your high school grades for each course taken, where each course has a different weight. The expectation value would be your weighted average of high school grades.