x = 2+3+3+4+5+5+5+7+7+910\frac{2+3+3+4+5+5+5+7+7+9}{10}102+3+3+4+5+5+5+7+7+9
=5010\frac{50}{10}1050
= 5
Variance = ∑(x−x)2N\frac{\sum (x-x)^2}{N}N∑(x−x)2
9+4+4+1+4+4+1610\frac{9+4+4+1+4+4+16}{10}109+4+4+1+4+4+16
= 4210\frac{42}{10}1042
= 4.2
