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.
This Khan Academy article reviews mean, median, and mode concepts with examples to help understand their application in statistics and probability.
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.
Practice finding the median of a data set. Like the mean, the median gives us a sense of the middle, or center, of the data.
A couple decides to keep having children until they have the same number of boys and girls, and then stop. Assume they never have twins, that the "trials" are independent with probability...
The net effect is that even if I don't know which one is definitely a boy, the other child can only be a girl or a boy and that is always and only a 1/2 probability (ignoring any biological weighting that girls may represent 51% of births or whatever the reality is).