The grades of a class of 9 students on a midterm report (x) and on the final examination (y) are shown below Use the data to complete parts (a) and (b). x 77 55 73 72 81 93 96 99 66 D y 81 73 79 36 47 83 99 99 68 (a) Estimate the linear regression line (Round the constant to one decimal place as needed. Round the coefficient to three decimal places as needed) (b) Estimate the final examination grade of a student who received a grade of 87 on the midterm report y= (Round to one decimal place as needed.).