Lesson · M.6.3

Mean, median and mode

Find the mean, median and mode of a small data set quickly and correctly, the three measures of central tendency the HESI A2 math subtest expects from a short list of numbers.

ObjectiveM.6.3Read4 minExam weightAlgebra and Statistics ≈ 18% of Mathematics

This lesson is part of the full Study Guide

Unlock every lesson, unit, and quiz across every subject. The Mathematics algebra and statistics unit is included.

See editions and pricing →

What you will be able to do

Calculate the mean of a data set by summing the values and dividing by the count.
Find the median of a data set with an odd or an even number of values.
Identify the mode, including when a set has no mode or more than one.

What the lesson concludes

Mean is the sum divided by the count. It is the only one of the three that uses every value in a calculation.
Median needs the values sorted first. With an even count, average the two middle values.
Mode is whichever value repeats most. A set can have no mode, one mode, or several.
These three answer different questions about the same list, so a data set can have three different-looking answers that are all correct.