Learn about Variance — part I
Jul 30, 2017 · 1 min read
In lesson 24 and lesson 25, we learned that the expected value (E[X]) is a descriptive quantity of the average (center) of a random variable X with a probability distribution function f(x). In the same way, a measure of the variability, i.e. deviation from the center, of the random variable is the variance V[X].
It is defined as the expected value of the squared deviation from the average.
