Drawing line of best fit through all points
"The Connect-the-Dots Error"
The Mistake in Action
Draw a line of best fit for the scatter graph.
Wrong: Student draws a line that goes through every single point, zigzagging across the graph
Why It Happens
Students treat "line of best fit" like "connect the dots" from primary school, or they think the line must touch every point.
The Fix
The line of best fit is a single straight line that shows the general trend.
Rules:
- Use a ruler for a straight line
- The line should have roughly equal points above and below
- It doesn't need to pass through any actual points
- It should pass through or near $(\bar{x}, \bar{y})$
Think of it as: The line that best represents where ALL the points are heading, not a path between them.
Spot the Mistake
Can you identify where this student went wrong?
Draw a line of best fit
Zigzag line through every point
Click on the line that contains the error.
Related Topics
Learn more about the underlying maths: