In the accompanying table, x is the tensile force applied to a steel specimen in thousands of pounds, and y is the resulting elongation in thousands of an inch: X Y 1 14 2 33 3 40 5 6 63 76 85 a) Find the equation of the least squares line, and use it to predict the elongation when the tensile force is 3.5 thousand pounds. b) Construct a 95% confidence interval for ẞ, the elongation per thousand pounds of tensile stress; c) Find 95% limits of prediction for the elongation of a specimen with x = 3.5 thousand pounds.