# বের করতে হবে Sum_of_all{(x-xmean)*(y-ymean)}, প্রতিটা (x,y) ভ্যালু দিয়ে
(x,y) => (1,4): (x-xmean)*(y-ymean) => {-2 * -31.2 = 62.4}
(x,y) => (2,12): (x-xmean)*(y-ymean) => {-1 * -23.2 = 23.2}
(x,y) => (3,28): (x-xmean)*(y-ymean) => {0 * -7.2 = 0}
(x,y) => (4,52): (x-xmean)*(y-ymean) => {1 * 16.8 = 16.8}
(x,y) => (5,80): (x-xmean)*(y-ymean) => {2 * -44.8 = 89.6}
Sum_of_all => {62.4+23.2+0+16.8+89.6} = 192