E(aX+b) and E(ax-b)

In this tutorial I show you the meaning of these functions and how to calculate it from a probability distribution table for a discrete random variable.

Extending E(X) to E(X ± a) and E(aX) : ExamSolutions - youtube Video

Var(X+a), Var(X-a) and Var(aX)

In this tutorial I show you several formulae that you can use to work these out based on Var(X). The video includes a short exercise.

Extending Var(X) to Var(X ± a) and Var(aX) : ExamSolutions - youtube Video

Why do these work like this?

Why does Var(a)=0, Var(X ± a) = Var(X) and Var(aX) = a²Var(X) : ExamSolutions - youtube Video