SAT Math: Writing a Linear Function from a Table of Values
24+ practice questions in Praczo
The concept, explained
- 1
From a table, compute the slope: pick any two (x, y) pairs and find m = (y₂ − y₁)/(x₂ − x₁).
- 2
Confirm linearity first: if the differences in y are constant for equal differences in x, the relationship is linear.
- 3
Once you have m, use one point and y = mx + b to solve for b.
- 4
Verify your equation by substituting a third point from the table — it should satisfy the equation.
- 5
If the table gives non-unit x-increments, the slope calculation still works — just use the actual Δx.
- ✗ Using the numbers from only the first row as the slope and intercept without computing Δy/Δx.
- ✗ Forgetting to check that the relationship is actually linear before writing a linear model.
SAT-style practice
A table shows: when x = 2, y = 7; when x = 5, y = 13. Which equation represents the linear relationship?
Ready to master this concept?
Praczo tracks your mastery on all 179 SAT concepts — not just broad topics. One sample question is a start; drilling to mastery is how scores move.
3-day free trial — no credit card required