7 find the value of the linear correlation coefficient r: the paired data below consist of the costs of advertising (in thousands of dollars) and the number of products sold (in thousands). cost 9 number 85 2 3 52 55 4 68 2 5 67 86 83 9 10 73 a) 0.708 b) 0.246 c) -0.071 d) 0.235