Section C: Forecasting Techniques (Total marks: 33 marks) Question 8 (6 marks) The heights X (in cm) and the weights Y (in kg) of 8 persons are as follows: X 147 150 152 157 160 163 Y 52 53 54 56 60 58 62 155 166 65 Points (147,52) (150,53) (152,54) (155,56 (157,60) (160,58) (163,62) (166,65) Total X; - * -9.25 -6.25 -4.25 -1.25 0.75 3.75 6.75 9.75 0 (x - 72 85.5625 39.0625 18.0625 1.5625 0.5625 14.0625 45.5625 95.0625 299.5 Yi - -5.5 -4.5 -3.5 -1.5 2.5 0.5 4.5 7.5 0 (y - y)2 30.25 20.25 12.25 2.25 6.25 0.25 20.25 56.25 148 (xi - x)(yi - y) 50.875 28.125 14.875 1.875 1.875 1.875 30.375 73.125 203 1250 = $1=1 Xi = 1250, x = 156.25 21=1 Yi = 460, y = = = 57.5 8 4 60 8 Required: Find Coefficient of Linear Correlation of X and Y. Hence say whether the height is positively correlated to the weight. cov(x,y) Hint: r = Sx*Sy