Recitation 4

Correlation and Regression Quiz

This quiz is self-graded. Athletes competing in a triathlon participated in a study where their finishing times x (in hours) and their myoglobin levels y (ng/mL) were recorded. The results for five athletes were

x:	4.90	4.70	5.35	5.22	5.20
y:	1590	1550	1360	895	865

1.

Find the means, standard deviations, and correlation coefficient of the variables.

2.

If you changed the units of measurement for the finishing tome from hours to minutes, what would the new means, standard deviations, and correlation be?

3.

Suppose you want to predict myoglobin level from finishing time. Find the equation of the appropriate least squares line.

4.

What myoglobin level would you predict for a finishing time of 5.00 hours. What about 8.00 hours? Is it reasonable to use the least squares line to predict for 8.00 hours?