Originally Posted by

**Sean12345** All I know is that for a discrete variable such as this the expected value is the product of the number of trials and the probability of $\displaystyle X$ happening on each trial. Since in this case the probability of $\displaystyle X$(Heads being shown) happening on each flip of the coin is the same $\displaystyle (1/2)$ then the expected value is $\displaystyle np$ where $\displaystyle n$ is the number of trials $\displaystyle (3)$ and $\displaystyle p$ is the probability of a heads being shown $\displaystyle (1/2)$ .