Q. 12 - Elementary Statistics

Question

12. In the context of regression analysis, what is an

a. outlier?

b. influential observation?

Step-by-Step Solution

Answer

a. Outliers are data points that lie far away from the regression line.

b. The regression equation changes considerably when a data point is removed that is influential.

Part (a) Step 1: Concept Introduction

Statistical regression analysis enables you to determine the relationship between two or more variables. Whenever, to predict a continuous dependent variable, then regression analysis has been used.

Part (a) Step 2: Explanation

The outlier is a data point that is significantly different from the regression line, in comparison with other data points.

Part (b) Step 3: Concept Introduction

Statistical regression analysis enables you to determine the relationship between two or more variables. Whenever, to predict a continuous dependent variable, then regression analysis has been used.

Part (b) Step 4: Explanation

In a regression equation, an influential point is a data point whose removal causes the equation to change greatly. 

An influential point is a data point that affects the slope of the regression line.