The equation to find the variance is :
[tex]s^2=\frac{\sum ^n_1(x-\bar{x})^2}{n-1}[/tex]So, first we will find the mean of the given data
The given data are : 6 , 7 , 8 , 9 , 10
mean = (6+7+8+9+10)/5 = 8
Then find ( x - x')
Variance =
[tex]\begin{gathered} \frac{(6-8)^2+(7-8)^2+(8-8)^2+(9-8)^2+(10-8)^2}{5-1} \\ \\ =\frac{(-2)^2+(-1)^2+(0)^2+(1)^2+(2)^2}{5-1}=\frac{4+1+0+1+4}{4}=\frac{10}{4}=2.5 \end{gathered}[/tex]