Drawing Line of Best Fit Scatter Plot Algebra Statistics
Published on May 5, 2026
Learn how to draw and approximate the line of best fit for data points on a scatter plot to understand trends in Algebra and Statistics.
Question
Answer
- Around x = 10, y is around 2-4.
- Around x = 20, y is around 4-6.
- Around x = 30, y is around 6-8.
- Around x = 40, y is around 8-10.
- Around x = 50, y is around 10-12.
- Around x = 60, y is around 12-14.
- Around x = 70, y is around 12-14.
- Around x = 80, y is around 14-16.
- Around x = 90, y is around 16-18.
- Around x = 100, y is around 18-20.
Let’s consider a point near the beginning of the trend, say when theater revenue is around 10 million dollars, the rental revenue is around 3 million dollars. So, a point could be (10, 3).
Let’s consider a point near the end of the trend, say when theater revenue is around 100 million dollars, the rental revenue is around 18 million dollars. So, a point could be (100, 18).
The slope of the line passing through
If x = 0, y = 4/3 ≈ 1.33. This is a reasonable starting point for the line, as some points are close to the y-axis with low y values.
If x = 10, y = 10/6 + 4/3 = 5/3 + 4/3 = 9/3 = 3. This matches our chosen point.
If x = 100, y = 100/6 + 4/3 = 50/3 + 4/3 = 54/3 = 18. This matches our chosen point.
Let’s pick a point where the line might pass near (0, 2).
Let’s pick another point where the line might pass near (80, 14).
Slope
Equation:
If x = 0, y = 2.
If x = 20, y = 3/20 * 20 + 2 = 3 + 2 = 5. Looking at the graph, at x=20, y is around 4-6. This is reasonable.
If x = 40, y = 3/20 * 40 + 2 = 6 + 2 = 8. At x=40, y is around 8-10. This is reasonable.
If x = 60, y = 3/20 * 60 + 2 = 9 + 2 = 11. At x=60, y is around 12-14. This is a bit low.
If x = 80, y = 3/20 * 80 + 2 = 12 + 2 = 14. This matches our chosen point.
If x = 100, y = 3/20 * 100 + 2 = 15 + 2 = 17. At x=100, y is around 18-20. This is a bit low.
Consider the point (20, 6) and (90, 17).
Slope
Equation:
If x = 0, y ≈ 2.86.
If x = 20, y = 11/70 * 20 + 20/7 = 22/7 + 20/7 = 42/7 = 6. (Matches)
If x = 40, y = 11/70 * 40 + 20/7 = 44/7 + 20/7 = 64/7 ≈ 9.14. (At x=40, y is around 8-10. Good.)
If x = 60, y = 11/70 * 60 + 20/7 = 66/7 + 20/7 = 86/7 ≈ 12.29. (At x=60, y is around 12-14. Good.)
If x = 80, y = 11/70 * 80 + 20/7 = 88/7 + 20/7 = 108/7 ≈ 15.43. (At x=80, y is around 14-16. Good.)
If x = 100, y = 11/70 * 100 + 20/7 = 110/7 + 20/7 = 130/7 ≈ 18.57. (At x=100, y is around 18-20. Good.)
The line passes through approximately (0, 2.86) and (100, 18.57).
So, we can draw a line from approximately (0, 3) to (100, 18.5).
Another way to draw it is by picking two points on the grid that appear to be on the line.
For example, we can draw a line passing through the point (0, 3) and another point around (60, 12).
Let’s check the slope between (0, 3) and (60, 12).
Equation:
Let’s check points:
x=0, y=3.
x=20, y = 0.1520 + 3 = 3 + 3 = 6. (Good, points around (20, 6))
x=40, y = 0.1540 + 3 = 6 + 3 = 9. (Good, points around (40, 8-10))
x=60, y = 0.1560 + 3 = 9 + 3 = 12. (Good, points around (60, 12-14))
x=80, y = 0.1580 + 3 = 12 + 3 = 15. (Good, points around (80, 14-16))
x=100, y = 0.15*100 + 3 = 15 + 3 = 18. (Good, points around (100, 18-20))