gpa is plotted against iq test scores for 78 7th grade students. the mean and standard deviation of the iq scores are: mean x = 108.9 and standard deviation of sx = 13.17. for the gpa: mean y = 7.447 and a standard deviation of sy = 2.10. correlation is r = 0.6337. find the least squares regression line. round all decimals to 3 places. (slope, y-intercept, and model)