1) Researchers investigating the association between the size and strength of muscles measured the forearm circumference (in inches) of 20 teenage boys. Then they measured the strength of the boys' grips (in pounds). Their data are plotted at the right.

80 70 60 50 Strength 40 + 10 11 12 13 14 Circum\fPredicted Cost = 55.52 + 82.1(carat) and R Squared = 98.7%