Question

Which of the following statements about outliers is true?1. Removing an outlier from a data set can have a major effect on theregression line.II. If you calculated the residual between the outlier and a regression linebased on the rest of the data, it would probably be largeIII. You will typically find an outlier horizontally distant from the rest of thedata along the x-axis.A. Ill onlyB. Il onlyОО ООC. I and Il onlyD. I only

Answer 1

Outliers:

Outliers are basically odd values in a data set meaning that they are significantly different from the rest of the values in the data set.

The presence and absence of outliers can greatly affect the regression line.

So, the statement I is absolutely true.

Residuals:

Residual is the difference between the actual value and the predicted value (calculated using regression equation)

Since the outliers are pretty far away from the usual values in the data set, the residual between the outlier and a regression line would probably be large.

So, statement II is also true.

Note that outliers can exist far away from the usual values in the data set both horizontally and vertically.

So, statement III is not true.

Therefore, option C is the correct answer.

C. I and Il only