What does a strong negative correlation look like on a scatter diagram?

A strong negative correlation on a scatter diagram looks like a tight cluster of points sloping downwards from left to right.

In more detail, a scatter diagram is a type of graph used to display the relationship between two variables. Each point on the graph represents a pair of values. When we talk about a strong negative correlation, we mean that as one variable increases, the other variable decreases in a consistent and predictable way. This relationship is visualised by the points forming a clear downward slope.

Imagine plotting the heights and weights of a group of people. If taller people tend to weigh less, the points on the scatter diagram would start high on the left side (representing tall people with lower weights) and move downwards to the right side (representing shorter people with higher weights). The points would be closely packed along this downward line, indicating a strong negative correlation.

In mathematical terms, the correlation coefficient (often denoted as 'r') quantifies the strength and direction of this relationship. For a strong negative correlation, 'r' would be close to -1. This means the points are not just randomly scattered but follow a clear, tight pattern sloping downwards.

Understanding scatter diagrams and correlations helps in analysing data and identifying trends. For example, if you were studying the relationship between study time and exam scores, a strong negative correlation would suggest that more study time is associated with lower exam scores, which might indicate an issue worth investigating further.