Question

1. a regression model was created for the data in the graph above (left). the residual plot for the model is given above (right). which of the following statements about the regression model is best? (a) a quadratic regression model was used and the model is appropriate. (b) a quadratic regression model was used and the model is not appropriate. (c) an exponential regression model was used and the model is appropriate. (d) an exponential regression model was used and the model is not appropriate.

Explanation:

Step1: Recall the property of a good regression model

A good regression model has a residual plot with no pattern.

Step2: Analyze quadratic regression

If a quadratic regression model was used, the residual plot would show a pattern (like a curve). But the given residual plot has no such pattern.

Step3: Analyze exponential regression

If an exponential regression model was used, the residual plot would show a pattern (either increasing or decreasing trend in spread). But the given residual plot has no such pattern.

Step4: Check the validity

Since the residual plot has no pattern, the model (quadratic in this case as per options) is appropriate.

Answer:

B. A quadratic regression model was used and the model is not appropriate.