Rata-rata
$$\mu = \frac{1}{N} \sum_{i=1}^N x_i$$ $$\bar{x} = \frac{1}{n} \sum_{i=1}^n x_i$$
Varian
$$\sigma^2 = \frac{1}{N} \sum_{i=1}^N (x_i - \mu)^2$$ $$s^2 = \frac{1}{n-1} \sum_{i=1}^n (x_i - \bar{x})^2$$
Distribusi Normal
$$f(x) = \frac{1}{\sqrt{2\pi \sigma^2}} \exp{\left(-\frac{1}{2}\frac{(x-\mu)^2}{\sigma^2}\right)}$$
Sumber: Rumus Statistik