Probability
Discrete Random Variables A random variable is a number whose value depends upon the outcome of a random experiement. Such as tossing a coin 10 times and let X be the number of Head.
A discrete random variable X has finitely countable values $x_i = 1, 2…$ and $p(x_i) = P(X = x_i)$ is called probability mass function.
Probability mass functions has following properties:
For all i, $p(x_i) > 0$ For any interval $P(X \in B) = \sum_{x_i \in B}p(x_i)$ $\sum_{i}p(x_i) = 1$ There are many types of discrete random variable……