TopicsStatistics › Outliers and Influential Points in Regression
Statistics · REG

Outliers and Influential Points in Regression

An outlier has a large residual. An influential point, when removed, substantially changes the slope. High leverage points are extreme in x.

StatisticsCommon Core DAT-1.DREGVerified correct ✓

Worked examples

A regression line is fit to 75 data points relating study hours (x) to exam scores (y). The resulting line is ŷ = 50 + 75x with r² = 0.85. A new data point (x = 2, y = 98) is added to the dataset. (a) Does this point appear to be an outlier? Explain using the regression line. (b) Would this point likely be influential? Explain what "influential" means in regression context. (c) After adding this point, would you expect r² to increase, decrease, or stay the same? Explain.
Answer:
A regression line is fit to 21 data points relating study hours (x) to exam scores (y). The resulting line is ŷ = 50 + 15x with r² = 0.85. A new data point (x = 2, y = 98) is added to the dataset. (a) Does this point appear to be an outlier? Explain using the regression line. (b) Would this point likely be influential? Explain what "influential" means in regression context. (c) After adding this point, would you expect r² to increase, decrease, or stay the same? Explain.
Answer:

Every problem on Pounce is generated and checked by code — never a wrong answer key.

Master Outliers and Influential Points in Regression

Code-verified problems at exactly the right level, explained the way your kid learns.

Start your free trial 🐾

Build up to this

More Statistics topics