Find the mean and variance for the data 6, 7, 10, 12, 13, 4, 8, 12

6, 7, 10, 12, 13, 4, 8, 12

Mean, $\bar{x}=\frac{\sum_{i=1}^{8} x_{i}}{n}=\frac{6+7+10+12+13+4+8+12}{8}=\frac{72}{8}=9$

The following table is obtained.

Variance $\left(\sigma^{2}\right)=\frac{1}{\mathrm{n}} \sum_{i=1}^{8}\left(\mathrm{x}_{i}-\overline{\mathrm{x}}\right)^{2}=\frac{1}{8} \times 74=9.25$