Math 1431 – Spring 2003 – Test #1 – Practice
Question 9 Answer

The scatterplot is:

  1. There does not seem to be any outliers. The pattern looks linear and this linear relationship seems to be relatively strong. The variables are negatively–associated.
  2. The correlation coefficient, r = –0.949.
  3. The least–regression line is = –0.41 x + 1025.9. Thus, the predicted winning time for 2020 is = –0.41 (2020) + 1025.9 = 196.3. The prediction is not very good because 2020 is far away from the data.

NOTE: The winning time for 2000 was 212.1!