Random variable

Definition

A random variable is a variable that takes on different numerical values, each with a certain probability. It represents the outcomes of a random phenomenon.

5 Must Know Facts For Your Next Test

1. A random variable can be either discrete or continuous.
2. The mean of a random variable is known as its expected value.
3. In hypothesis testing, random variables are used to create test statistics.
4. The variance of a random variable measures its spread or dispersion.
5. Random variables are essential in calculating confidence intervals and p-values.

Review Questions

• What is the difference between discrete and continuous random variables?
• How do you calculate the expected value of a random variable?
• What role do random variables play in hypothesis testing?

Related terms

Discrete Random Variable:

A type of random variable that can take on a countable number of distinct values.

Continuous Random Variable:

A type of random variable that can take on an infinite number of values within a given range.

Expected Value:

The long-term average value of repetitions of the experiment it represents, calculated as the weighted average of all possible values.