Answer
$a. Σx = 54$
$b. Σy = 113.6$
$c. Σx^{2}= 2916$
$d. Σxy = 742.7$
$e. Σx^{2}y = 331257.6$
$f. Σy^{2} = 12904.96$
Work Step by Step
$a. Σx = 3+7+5+9+12+8+10 = 54$
$b. Σy = 28.4+17.2+21.6+13.9+6.3+16.8+9.4 = 113.6$
$c. Σx^{2}= 54^{2} = 2916$
$d. Σxy =(3\times28.4)+(7\times17.2)+(5\times21.6)+(9\times13.9)+(12\times6.3)+(8\times16.8)+(10\times9.4)= 742.7$
$e. Σx^{2}y =(2916\times113.6) = 331257.6$
$f. Σy^{2} = 113.6^{2} = 12904.96$
