Sample variance (dispersion)
$$s^{2} = \frac{(x_1-x_{v})^{2}\cdot m_1+(x_2-x_{v})^{2}\cdot m_2+(x3-x_{v})^{2}\cdot m3}{n-1}$$
s^2 - sample variance (dispersion)
x1, x2, x3 ... - sample values
m1, m2, m3 ... - frequencies of sample elements
x_v - sample mean (average)
n - number of sample elements
x1, x2, x3 ... - sample values
m1, m2, m3 ... - frequencies of sample elements
x_v - sample mean (average)
n - number of sample elements
Find
It is known that:
= 