# Least-Squares Regression

Lead Author(s): **University of Colorado Boulder**

Source: **UC Boulder PhET**

Student Price: **FREE**

Create a scatter plot or use real-world data and try to fit a line to it! Explore how individual data points affect the correlation coefficient and best-fit line.

This content is licensed under the Creative Commons Attribution 4.0 International License.

Content Index

# Least-Squares Regression

### Topics

- Linear Regression
- Correlation
- Residuals
- Outlier
- Data

### Description

Create your own scatter plot or use real-world data and try to fit a line to it! Explore how individual data points affect the correlation coefficient and best-fit line.

### Sample Learning Goals

- Interpret r (the correlation coefficient) as data points are added, moved, or removed.
- Interpret the sum of the squared residuals while manually fitting a line.
- Interpret the sum of the squared residuals of a best-fit line as a data point is added, moved, or removed.
- Compare the sum of the squared residuals between a manually fitted line and the best-fit line.
- Determine if a linear fit is appropriate.