8th Grade · Statistics & Probability
Residual
8.SP.A.2
Definition
The difference between an observed data value and the value predicted by the line of best fit, measured vertically. Small residuals indicate the line fits the data well.
Teach it
Where it is taught, with guided notes, practice, homework, an exit ticket and an interactive Teacher Deck.
Examples
- Actual = 80, predicted = 74, residual = 80-74 = 6.
- Points above the line have positive residuals; points below have negative residuals.
Key rule
Residual = actual value minus predicted value.
Memory hook
How far off the prediction was, for one point.