Year 7 Unit 1: Analysing and Displaying Data

Positive correlation

An upward trend in the line of best fit. As one variable increases, the other increases.

Average

The central or typical value in a data set: mode, median or mean.

Mode

The most common/frequent value from a set of data

Median

The middle value when the data is in order

Mean

Add up all the numbers and divide the total by how many numbers there are

Range

A measure of the spread of data,
= largest value - smallest value

Quartiles

Divide a data set into quarters. After finding the median, find the median of the lower and upper halves of the data.

Inter-Quartile Range

A measure of spread of the middle 50% of the data,
IQR = Upper Quartile - Lower Quartile

8
Scatter graph

A diagram whose purpose is to establish the relationship between two variables

Line of best fit

A straight line drawn through a scatter graph to show a correlation.

Correlation

The relationship between two variables shown on a scatter graph.

Negative correlation

A downward trend in the line of best fit. As one variable increases, the other decreases.

No correlation

No linear relationship between the two variables shown on the scatter graph.

Strong correlation

A close relationship between the two variables shown on a scatter graph.

Weak correlation

A general relationship between two variables shown on a scatter graph.

Outlier

A value that lies outside most of the other values of a data set.