ScattergramsBy Tabby Goulty

Line of best fit – it is a line that goes roughly through the middle of all the points on the graph. IT DOES NOT CONNECT ALL THE POINTS.

Positive correlation – when the points rise from left to right, meaning the numbers on the x and y axis are similar.

Negative correlation – when the points decrease in height from left to right, meaning as the x axis increases the y axis decreases.

No correlation – when to points are not connected in any way and there is no pattern.

Strong – the points are closer to the line of best fit. Weak – the points are further away from the line of best fit. Anomalies – points that don’t fit in with the pattern of the

others.

Keywords

Keyword examples

Weak

Anomalies

Line of best fit

Negative correlation

Positive correlation

Strong

x

Height (cm)

155 122 133 159 147 109 80 72 96 52 120 115 142

Arm span (cm)

150 119 129 160 142 100 77 71 91 55 111 113 143

Example with steps

40 60 80 100 120 140 160 1800

50

100

150

200

Chart showing the connections between arm span and height.

Height

Arm

sp

an

1. Draw out a y and x axis, it doesn’t matter which is labelled which, height or arm span. I will do height as x and arm span as y.

2. Draw a line upwards from (for example) 155 on the x axis, and then along from (for example) 150 and where the lines cross draw an x. Do this for all the figures.

3. Draw a line using a ruler that is at the centre of the general trend of all the pints. This is the line of best fit.