## 2.1 Discrete Probability Distributions and Mass Functions

#### Discrete Probability Distributions

- The probability distribution for a discrete random variable is a description all the possible values of the random variable, and its corresponding probability.

- Since it is discrete (means there is supposedly/usually a finite number of outcomes), we can express the probability distribution in a table.

- We can describe the probability distribution with the function

p(x)=\operatorname{Pr}(X=x)

where X is the random variable and x is the corresponding values.

- The function above is called a discrete probability function or a probability mass function (pmf).