B4 Scatter Graphs and Linear Line Trends
Unit 7: Business Decision Making
Scatter (XY) graphs can be used to display two sets of data to see if there is a correlation between them.
When both variables increase, there is a positive correlation. An example of positive correlation could be rainfall and umbrella sales. When one variable increases and the other decreases, this is a negative correlation. An example of negative correlation could be rainfall and ice cream sales. When no relationship can be found between the two variables, there is no correlation.
A trend line can be drawn though the centre of the points to make the graph easier to interpret. This line can be extrapolated to predict future trends.
