1. If the coefficient of determination is 0.618, what percentage of the variation in the data about the regression line is unexplained?

38.2%

61.8%

30.2%

68.1%

2. The equation used to predict how many days it takes a 15-year old to read the first Harry Potter book is = 1.5 + 2.82x1 - 1.04x2 days, where x1 is the weekly hours of other activities and x2 is the reading grade level. Use this equation to predict how many days it will take to read this book for someone with 12.8 weekly hours of other activities and a 10.9 reading grade level.

26.26 days

74.43 days

18.93 days

25.82 days