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Lines of Best Fit & Predictions — Easy Worksheet 1
Grade 8 · MathSheets Name: ____________________ Date: __________
Each scatter plot shows a line of best fit. Answer with a number, or write the equation as y = mx + b.
How to solve
A line of best fit y = mx + b follows the trend of the data. To predict, substitute the x-value into the equation. The slope m is the predicted change in y for each 1 unit increase in x, and the y-intercept b is the predicted value when x = 0. To write the equation, pick two points on the line, find the slope, then find b.
Example
The line of best fit is y = -2x + 42. Predict y when x = 5.
Answer: 32
Not quite. The answer is
💡 Substitute x = 5 into the equation: y = 9 × 5 + 8 = 45 + 8 = 53.
✓ Correct!
Not quite. The answer is
💡 Substitute x = 5 into the equation: y = 9 × 5 + 8 = 45 + 8 = 53.
💡 How to solve: Lines of Best Fit & Predictions
A line of best fit y = mx + b follows the trend of the data. To predict, substitute the x-value into the equation. The slope m is the predicted change in y for each 1 unit increase in x, and the y-intercept b is the predicted value when x = 0. To write the equation, pick two points on the line, find the slope, then find b.
Try a similar one
The line of best fit is y = 3x + 49. Predict y when x = 6.
✓ You've got it! Press Next to keep going. Not yet — the answer is . Read the steps above once more.
Not quite. The answer is
💡 In y = mx + b, the slope m is the change in y for each 1 more in x. Here m = 2, so the predicted y goes up by 2 for each additional week. The answer is 2.
✓ Correct!
Not quite. The answer is
💡 In y = mx + b, the slope m is the change in y for each 1 more in x. Here m = 2, so the predicted y goes up by 2 for each additional week. The answer is 2.
💡 How to solve: Lines of Best Fit & Predictions
A line of best fit y = mx + b follows the trend of the data. To predict, substitute the x-value into the equation. The slope m is the predicted change in y for each 1 unit increase in x, and the y-intercept b is the predicted value when x = 0. To write the equation, pick two points on the line, find the slope, then find b.
Try a similar one
The line of best fit is y = 4x + 50. Predict y when x = 2.
✓ You've got it! Press Next to keep going. Not yet — the answer is . Read the steps above once more.
Not quite. The answer is
💡 Substitute x = 3 into the equation: y = 14 × 3 + 9 = 42 + 9 = 51.
✓ Correct!
Not quite. The answer is
💡 Substitute x = 3 into the equation: y = 14 × 3 + 9 = 42 + 9 = 51.
💡 How to solve: Lines of Best Fit & Predictions
A line of best fit y = mx + b follows the trend of the data. To predict, substitute the x-value into the equation. The slope m is the predicted change in y for each 1 unit increase in x, and the y-intercept b is the predicted value when x = 0. To write the equation, pick two points on the line, find the slope, then find b.
Try a similar one
The line of best fit is y = 14x + 7. Predict y when x = 7.
✓ You've got it! Press Next to keep going. Not yet — the answer is . Read the steps above once more.
Not quite. The answer is
💡 Substitute x = 0: y = 8 × 0 + 11 = 11. This is the y-intercept b.
✓ Correct!
Not quite. The answer is
💡 Substitute x = 0: y = 8 × 0 + 11 = 11. This is the y-intercept b.
💡 How to solve: Lines of Best Fit & Predictions
A line of best fit y = mx + b follows the trend of the data. To predict, substitute the x-value into the equation. The slope m is the predicted change in y for each 1 unit increase in x, and the y-intercept b is the predicted value when x = 0. To write the equation, pick two points on the line, find the slope, then find b.
Try a similar one
The line of best fit is y = 2x + 7. Predict y when x = 2.
✓ You've got it! Press Next to keep going. Not yet — the answer is . Read the steps above once more.
Not quite. The answer is
💡 Substitute x = 4 into the equation: y = −3 × 4 + 48 = −12 + 48 = 36.
✓ Correct!
Not quite. The answer is
💡 Substitute x = 4 into the equation: y = −3 × 4 + 48 = −12 + 48 = 36.
💡 How to solve: Lines of Best Fit & Predictions
A line of best fit y = mx + b follows the trend of the data. To predict, substitute the x-value into the equation. The slope m is the predicted change in y for each 1 unit increase in x, and the y-intercept b is the predicted value when x = 0. To write the equation, pick two points on the line, find the slope, then find b.
Try a similar one
The line of best fit is y = 13x + 14. Predict y when x = 7.
✓ You've got it! Press Next to keep going. Not yet — the answer is . Read the steps above once more.
Not quite. The answer is
💡 In y = mx + b, the slope m is the change in y for each 1 more in x. Here m = 2, so the predicted y goes up by 2 for each additional week. The answer is 2.
✓ Correct!
Not quite. The answer is
💡 In y = mx + b, the slope m is the change in y for each 1 more in x. Here m = 2, so the predicted y goes up by 2 for each additional week. The answer is 2.
💡 How to solve: Lines of Best Fit & Predictions
A line of best fit y = mx + b follows the trend of the data. To predict, substitute the x-value into the equation. The slope m is the predicted change in y for each 1 unit increase in x, and the y-intercept b is the predicted value when x = 0. To write the equation, pick two points on the line, find the slope, then find b.
Try a similar one
The line of best fit is y = 5x + 45. Predict y when x = 5.
✓ You've got it! Press Next to keep going. Not yet — the answer is . Read the steps above once more.
Not quite. The answer is
💡 Substitute x = 7 into the equation: y = 11 × 7 + 5 = 77 + 5 = 82.
✓ Correct!
Not quite. The answer is
💡 Substitute x = 7 into the equation: y = 11 × 7 + 5 = 77 + 5 = 82.
💡 How to solve: Lines of Best Fit & Predictions
A line of best fit y = mx + b follows the trend of the data. To predict, substitute the x-value into the equation. The slope m is the predicted change in y for each 1 unit increase in x, and the y-intercept b is the predicted value when x = 0. To write the equation, pick two points on the line, find the slope, then find b.
Try a similar one
The line of best fit is y = 5x + 50. Predict y when x = 8.
✓ You've got it! Press Next to keep going. Not yet — the answer is . Read the steps above once more.
Not quite. The answer is
💡 Substitute x = 0: y = −3 × 0 + 63 = 63. This is the y-intercept b.
✓ Correct!
Not quite. The answer is
💡 Substitute x = 0: y = −3 × 0 + 63 = 63. This is the y-intercept b.
💡 How to solve: Lines of Best Fit & Predictions
A line of best fit y = mx + b follows the trend of the data. To predict, substitute the x-value into the equation. The slope m is the predicted change in y for each 1 unit increase in x, and the y-intercept b is the predicted value when x = 0. To write the equation, pick two points on the line, find the slope, then find b.
Try a similar one
The line of best fit is y = -4x + 69. Predict y when x = 2.
✓ You've got it! Press Next to keep going. Not yet — the answer is . Read the steps above once more.
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Lines of Best Fit & Predictions — Easy Worksheet 1
Each scatter plot shows a line of best fit. Answer with a number, or write the equation as y = mx + b.