## Random Variables and Probability Distributions

This section first defines discrete and continuous random variables. Then, it introduces the distributions for discrete random variables. It also talks about the mean and variance calculations.

- The probability distribution of a discrete random variable is a listing of each possible value taken by along with the probability that takes that value in one trial of the experiment.
- The mean of a discrete random variable is a number that indicates the average value of over numerous trials of the experiment. It is computed using the formula .
- The variance and standard deviation of a discrete random variable are numbers that indicate the variability of over numerous trials of the experiment. They may be computed using the formula , taking the square root to obtain .