(a) A bivariate set of data (x,y) has a correlation coefficient R and a regression line of y on x given by y = Ax + B. Are the statements below correct, possible or false? Justify your answer in each case. (i) If R is negative, then A is negative. [ 2] (ii) Two bivariate sets of data that have the same value of R have the [ 2 ] same regression line. (iii) If R is weak, then the regression line gives less reliable predictions. [ 2 ] (iv) Adding more data points makes the correlation stronger. [2 ] (b) The scatter diagram below represents data sets X and Y. 250 200 150 100 50 20 40 60 80 100 120 X (i) Estimate the correlation coefficient using the scatter diagram. [2 ] (ii) By looking at the diagram, estimate the equation of the regression [ 5 ] line of y on x. Give a verbal description of what the equation tells you about the two data sets. How reliable is this equation? (iii) Based on your answer to (ii), predict the value of variable y when [ 5 ] x = 120 and when x = 45. Which value gives the more reliable