Last updated: October 22, 2026 · Written by the Math Made Easy math teachers
Looking for a line of best fit quiz? Then this Grade 8 quiz on Fitting Lines to Data and Making Predictions asks 10 multiple-choice questions with instant feedback. Ten multiple-choice questions check how to read, write, and use trend-line models. Think about the units for every slope and intercept, and read the explanations to find the exact slip behind each wrong choice.
Standards: 8.SP.A.2, 8.SP.A.3 · Level: Grade 8
What this Fitting Lines to Data and Making Predictions quiz checks
- A line of best fit follows the trend with points on both sides; it need not touch any point.
- To write the model, find the slope from two points on the line and read the y-intercept.
- Slope = change in y per 1 unit of x; intercept = predicted y at x = 0.
- Substitute x to predict y, or solve for x to reach a target.
- Predictions far outside the data are unreliable.
The 10 questions of the quiz
- In the model y = 4x + 10, what does the slope 4 mean?
- In the model y = 4x + 10, what does the y-intercept mean?
- Use y = −3x + 50 to predict y when x = 8.
- Which equation matches the trend line?
- Which line fits the data better?
- What is a line of best fit?
- Why is it risky to predict far outside the range of the data?
- A trend line passes through (2, 7) and (6, 19). What is its slope?
- Use y = 1.5x + 6. For what x is y = 21?
- A trend line has a negative slope. What does that tell you about the data?
After the quiz
Missed a question? Reread the Fitting Lines to Data and Making Predictions lesson, then take the quiz again. Next, solve the Grade 8 worksheet on Fitting Lines to Data and Making Predictions, one star first, then two and three stars. Finally, take the chapter test under real conditions, without notes and with a timer.