Line of Best Fit

A line of best fit is a straight line drawn through a scatter plot that best represents the overall trend of the data. It can be used to estimate values and describe the relationship with an equation y = mx + c.

If a line of best fit has equation y = 3x + 5, then at x = 4, y = 3(4) + 5 = 17.

The gradient between two points on the line is found the same way as for any straight line: (y₂ − y₁) ÷ (x₂ − x₁).

Estimate a value using a line of best fit, or find its gradient from two points.

Continue exploring related topics:

• Scatter Plots - Plotting Paired Data
• Correlation - Describing Relationships in Data
• Gradient-Intercept Form - Building y = mx + c from Points