a) For a data set consisting of points in R2, with x as the independent variable and y as the dependent variable, explain what quantity is minimised by the least square regression line y = a + Bx (2 marks) b) Let C be the following data set: X 3 12 4 y 4 3 1 5 15 Calculate the least squares regression line for this data set and use it to estimate a value of y, for i=0,1; -1.5, 16 = 10. (5 marks) c) Make an argument as to whether or not your estimates in part (b) may be reasonable