Discrete Random Variables
A collection of videos, activities and worksheets that are suitable for A Level Maths.
What is the meaning of Var(X) and how to calculate it for a discrete random variable?
The Expected Mean E(X)
The meaning of this function, Expected Mean E(X), and how to use it to calculate the expected mean for a discrete random variable.
Extending E(X) to E(X ± a) and E(aX)
What these functions mean, and how to use them.
Variance : Var(X)
The meaning of Var(X) and how to calculate it for a discrete random variable.
Extending Var(X) to Var(X ± a) and Var(aX)
I show you what these functions mean, and how to use them.
Why does Var(a)=0, Var(X ± a) = Var(X) and Var(aX) = a2Var(X)?
Non formal proof of these results.
The meaning and calculation of E(X2)
In this tutorial I show you the meaning of this function and how to calculate it for a discrete random variable.
Try out our new and fun Fraction Concoction Game.
Add and subtract fractions to make exciting fraction concoctions following a recipe. There are four levels of difficulty: Easy, medium, hard and insane. Practice the basics of fraction addition and subtraction or challenge yourself with the insane level.
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