# MDM4U Practising Expected Value – 2015-11-16

We worked some more on Expected Value, taking special notice of random variables with the Uniform Probability Distribution.

The Expected Value of a random variable $X$ is

$latex E(X)=\sum_{i=1}^{n}{P(x_i)\cdot x_i}$

If $X$ has a uniform distribution, $P(x_i) = \frac{1}{n}$ for every outcome $x_i$, so we can simplify the expected value:

$latex E(X)=\frac{1}{n}\sum_{i=1}^{n}{x_i}$

Need some practice? Try questions starting on page 375.

We started to talk really briefly about the Binomial Distribution – that’s the plan for tomorrow.