Expectation of Random Variable X

To study a random variable, we use different measures like: Expectation, Variance, Standard Deviation and Covariance etc.

Expectation of RV:

It is an important concept of probability theory. Expected value is also known as mean or average. To find mean of random variable, each possible value of X is multiplied by its respective probability. Then add up all these products to find expected value.

EXPECTED VALUE = MEAN = AVERAGE VALUE

Properties of expectation

1. E[aX] = a E[X]
2. E[aX+b] = a E[X] + b
3. E[aX₁ + b X₂] = a E[X₁] + b E[X₂]

Where a and b are some constants.