Question

The correlation between a  cereal's fiber and potassium contents is r=0.905.  What fraction of the variability in potassium is accounted for by the amount of fiber that servings  contain? ___________ %(Round to the nearest tenth as  needed.)

Answer 1

The correlation between the two substances can be expressed as follow:

$F=r\cdot P=0.905P$

Where F is the fiber and P stands for potassium

If we transform the correlation (r) into a percentage, we get

$0.905\to90.5\text{percent}$

which rounded to the nearest tenth becomes

$91\text{percent}$