3
Mathematical Expectation
Prerequisites
Before you start reading this unit, you should:
- Be able to differentiate between discrete and continuous random variables
- Be familiar with pmf and pdf
- Calculate marginal density of random variables
Learning Objectives
After going through this unit, you would be able to
- Understand the expectation, variance, conditional mean, Chebychev’s theorem, moments, moment generating function, and characteristic function
- Calculate expectation, variance, conditional mean, given joint density functions of X and Y
- Apply Chebychev’s theorem to a random variable with some mean and variance
INTRODUCTION
Consider for instance, a salesman’s average monthly income. This average may not be equal to any of his monthly pay. ...