Many high school students take either the SAT or the ACT. However, some students take both. Data were collected from 60 students who took both college entrance exams. The average SAT score was 912...

Many high school students take either the SAT or the ACT. However, some students take both. Data were collected from 60 students who took both college entrance exams. The average SAT score was 912 with a standard deviation of 180. The average ACT score was 21 with a standard deviation of 5. The correlation between the two variables equals 0.817.
(a) To predict the SAT score (y) from a student’s ACT score (x), what is the equation of the least-squares regression line? (b) What fraction of the variation in the values of the SAT scores is accounted for by the linear relationship between SAT and ACT scores?