Skip to content
kuazaraKuazara
Log in

Mathematics · Data and probability

Reading data: mean, median and mode

If a team scores "10 points on average", did every player score 10? Learn to calculate the mean, median and mode, and see how outliers affect each of these measures.

  • 20 min
  • 1 simulation
  • Mini quiz

Updated:

Preview

The question

Your school basketball team scored 60 points in a match with 6 players. The newspaper wrote: "The players scored 10 points on average." But when you look at the scoresheet, you see that one player scored 40 points on their own, while the others scored between 2 and 6. Does "an average of 10" really describe this team well? Are there other ways to sum up data with a single number?

Try it yourself

No account needed: change the values and check your answer. Some simulations ask for a prediction before they start; it doesn't matter whether it's right or wrong.

Number line

Average goals per match

Drag the point or use the buttons to move in steps of 0.5. When you reach the right value, press Check.

Prediction

Predict first

If the team scored 1 or 2 goals in most matches, where do you think the mean falls?

It doesn’t matter whether you’re right; the simulation opens once you choose.

Share: Share to Google Classroom (opens in a new tab)

Embed the simulation on your site

Paste this code into the HTML of your blog or school site. Visitors try the simulation without an account; no progress is saved.

The embedded page sets no cookies and does no tracking. A small link back to Kuazara sits underneath.

Log in to continue

The rest of the lesson is waiting for you, with a mini quiz. Creating an account is free.

Start for freeLog in

Frequently asked

5 questions

How do I work out the mean?

Add up all the values and divide by how many values there are. The mean of 4, 6 and 8 is (4 + 6 + 8) ÷ 3 = 6. The mean is like sharing the total out equally.

How do I find the median?

First put the data in order from smallest to largest, then take the value exactly in the middle. If there is an even number of values, find the mean of the middle two: the median of 2, 4, 6, 8 is (4 + 6) ÷ 2 = 5.

What is the mode, and can there be more than one?

The mode is the value that appears most often. If several values share the highest count there can be more than one mode; if no value repeats, there is no mode.

Which measure does an outlier affect most?

The mean. For the data 3, 4, 5, 6 and 100 the mean is 118 ÷ 5 = 23.6, but the median stays at 5. That is why, when there are outliers, the median can describe the "typical" value better.

Does the mean have to be one of the values in the data?

No. The mean is the result of sharing out. A group can have an average of 2.5 children per family, yet no family has half a child.