Use the Correlation and Regression applet for Exercises 76–78.

Question 4.278

77. The blue section of the thermometer is a measure of the sum of squares error, which is the total squared vertical distance from the data points to the actual regression line. Recall that the least-squares regression line minimizes this distance. The green section of the thermometer tells you how much “extra” squared error you get from using the line you constructed in Exercise 76(a).

  1. Adjust the line you drew in Exercise 76(a) by clicking and dragging on the points until the green section of the thermometer has disappeared.
  2. What does the disappearance of the green part tell you about the adjusted line you constructed?
  3. Will the line now coincide with the least-squares regression line?

4.3.77

(a) Answers will vary. (b) That your adjusted line matches the least squares regression line (c) Yes