**This is the students’ version of the page. Log in above for the teachers’ version.**

Prerequisites

- S2a – Frequency tables (for Part 2 of this lesson)

# Part 1 – Finding the mean from a list

Teacher resources for Part 1

Links to past exam and UKMT questions

**Teachers**: log in to access these.

### Visual representation of the mean

### Another visual representation of the mean

In the applet below, you can:

- adjust the number of values in the set using the slider;
- adjust each value in the set using the relevant + or – button; and
- click the green button to show the mean and click the pink button to hide the mean.

Consider these questions:

- What is the mean of this set of values?
- If you add 1 to one of the values, what will happen to the mean?
- If you subtract 1 from one of the values, what will happen to the mean?
- What do you have to add to any one of the values to increase the mean of the set by 1?
- If you add 1 to all of the values what happens to the mean?
- If you double all of the values, what happens to the mean?
- You want to include an extra value in the list. What does it have to be in order to leave the mean unchanged?

# Part 2 – Mean from a frequency table

Teacher resources for Part 1

**Teachers**: log in to access the following:

Links to past exam questions

**Teachers**: log in to access these.

In the real world

**Teachers**: log in to view this content.