Exercise 1.2 gives the age x1, measured in years, as well as the selling price x2, measured in thousands of dollars, for n 10 used cars. These data are reproduced as follows: 1 2 3 3 4 5 6 8 9 11 18.95 19.00 17.95 15.54 14.00 12.95 8.94 7.49 6.00 3.99 (a) Use the results of Exercise 1.2 to calculate the squared statistical distances (x, x)'S'(x, x). j = 1,2,..., 10, where x = [1,2]. - (b) Using the distances in Part a, determine the proportion of the observations falling within the estimated 50% probability contour of a bivariate normal distribution. (c) Order the distances in Part a and construct a chi-square plot. (d) Given the results in Parts b and c, are these data approximately bivariate normal? Explain.