Uniform Density
Interval
$$\mathbb{E}[X] = \int_1^{11} x * \frac{1}{11-1} dx \\ = \frac{11+1}{2} = 6$$
$$Var(X) = \mathbb{E}[(X-\mathbb{E}[X])^2] \\ = \mathbb{E}\left[\left(x- 6 \right)^2\right]$$
$$ = \int_1^{11} \left(x-6\right)^2 * \frac{1}{11-1} dx \\ = \frac{(11-1)^2}{12} = 8.\overline{33}$$