Discrete Probability Distributions (Edexcel A-Level Further Mathematics): Flashcards

Value that can only take certain fixed values (countable)

When its value depends on chance

List/formula of all outcomes of $X$ and their probabilities

$E(X) = Sigma xp$

Mean score per turn/throw

$E(X^2) = Sigma x^2 p$

$ext{Var}(X) = E(X^2) - E(X)^2$

When you have the entire population data

When estimating population parameters from a sample

s^2 = rac{n}{n-1} sigma^2