Lesson 5 of 12Article17 min
Random Variables & Expectation
A random variable X assigns a number to each outcome. Discrete: countable values with pmf p(x). Continuous: density f(x) where probabilities are areas.
Discrete vs continuous
A random variable X assigns a number to each outcome. Discrete: countable values with pmf p(x). Continuous: density f(x) where probabilities are areas.
Linearity of expectation holds even when variables are dependent — one of the most useful facts in probability.