You want to be able to predict a man's shoe size based on his height. You have gathered this information from your male classmates: the average height of the men in your class is 68 inches, and the standard deviation is 1 inch. The mean shoe size is size 10, and the standard deviation is 1. The r-value between these two variables is +0.50. Strength guidelines for the r-value: (0 – 0.4 is weak; 0.4 – 0.6 is moderate, 0.6 – 1 is strong)
1. Which variable is the independent variable?
2. Which variable is the dependent variable?
3. What is the interpretation of r?
4. What is the interpretation of r2?
5. What does "a" equal?
6. What does "b" equal?
7. What is the full regression equation?
8. What is the predicted shoe size of a guy who is 72 inches tall?
9. If that same guy actually wears size 13 shoes, what is the residual equal to?
10. For the same guy: did the equation over or underestimate his shoe size?