An economist wants to determine the relation between one's FICO score, x, and the interest rate of a 36-month auto loan, y. The given data represent the interest rate (in percent) a bank would offer on a 36-month auto loan for various FICO scores. Credit Score, X Interest Rate (percent), y 545 18.982 595 17.967 640 12.218 675 8.612 705 6.680 750 5.150 a) Find the least-squares regression line treating the FICO score, x, as the explanatory variable and the interest rate, y, as the response variable. b) Interpret the slope. c) Interpret the y-intercept, if appropriate. d) Predict the interest rate a person would pay if her FICO score was 523