Question

The scatter plot represents the purchase prices and selling prices of X-ray machines made by five different manufacturers. Which of the following points show errors of prediction or residuals?

Answer Choices :
Points (14, 25) and (15, 25)
Points (15, 25) and (18, 26)
Points (14, 25) and (16, 25)
Points (12, 24) and (18, 26)

Answer 1

As seen in the image, all of the prediction points are found on the line except for points (14,25) and (16,25). Therefore, these points contain errors in prediction.

Answer 2

The points on the scatter plot show the different predictions. The straight line drawn is called the line of regression. Errors in prediction for each point can be determined by drawing a vertical line from the point to the line of regression. As seen in the image, all of the prediction points are found on the line except for points (14,25) and (16,25). Therefore, these points contain errors in prediction.