The correlation coefficient (r) between the number of hours worked x and the amount of money earned y is 0.456 what percent of the variation in the amount of money earned can be explained by differences in the number of hours worked a : 79.2% b: 54.4% c: 45.6% d: 20.8%

The percent of the variation in the dependent variable that can be explained by the independent variable is called coefficient of determination, which is r^2. In this case, r = 0.456. So r^2 = 0.456^2 = 0.208. That means 20.8% of the variation in the amount of money earned can be explained by differences in the number of hours worked.