Learn about mean, median, and mode with Khan Academy's comprehensive review of these fundamental concepts in statistics.
The mean (average) of a data set is found by adding all numbers in the data set and then dividing by the number of values in the set. The median is the middle value when a data set is ordered from least to greatest. The mode is the number that occurs most often in a data set.
Practice calculating the mean (average) of a data set. The mean gives us a sense of the middle, or center, of the data.
Here we give you a set of numbers and then ask you to find the mean, median, and mode. It's your first opportunity to practice with us!
Learn how to calculate the mean by walking through some basic examples & trying practice problems.
Key idea: We can think of the mean as the balancing point , which is a fancy way of saying that the total distance from the mean to the data points below the mean is equal to the total distance from the mean to the data points above the mean.
Mean absolute deviation (MAD) of a data set is the average distance between each data value and the mean. Mean absolute deviation is a way to describe variation in a data set. Mean absolute deviation helps us get a sense of how "spread out" the values in a data set are.