Calculating the Mean
Calculate and interpret the mean as an average of a data set
What a learner can do afterwards
- Calculate the mean of five test scores: 72, 85, 90, 68, 95
- Explain what the mean represents and how it differs from individual data values
- Find a missing data value given the mean and all other values
The lesson
The mean is one kind of average. To find it, add up every value in a data set. Then divide that total by how many values there are.
Five test scores are 72, 85, 90, 68, and 95. Add them: 72+85+90+68+95=410. Divide by 5 scores: 410÷5=82. The mean score is 82.
The mean can be different from every single value in the data set. That is normal. It still describes the whole group well.
Four rounds of a game have a mean score of 6. Three of the rounds scored 5, 8, and 3. First find the total: 6×4=24. Then subtract the known scores: 24-5-8-3=8. The missing round scored 8.
Mean equals the total of all values divided by how many values there are.
Watch it
Where it sits
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.