Question

The average of the square of first 7 natural number?

Answer 1

1 -1
2 -4
3- 9
4 - 16
5 - 25
6 - 36
7 - 49
8 - 64

1 + 4 + 9 + 16 + 25 + 36 + 49 / 2 = 70

Answer 2

Average
$= \frac{sum \: of \: all \: obsevations}{number \: of \: all \: observations} \\ = \frac{ {1}^{2} + 2 ^{2} + {3}^{2} + {4}^{2} + {5}^{2} + {6}^{2} + {7}^{2} }{7} \\ = \frac{1 + 4 + 9 + 16 + 25 + 36 + 49}{7} \\ = \frac{140}{7} = 20$