NTU notes 6422quiz review (1-3 sections)

1 variance

Sample variance

  Total variance

2 Discrete coefficient coefficient of variation

（ percentage ）

3 Chebyshev's law

          For all the data , Its mean value is known to be μ The standard deviation is s, So for anything greater than 1 Of k,[μ-ks,μ+ks] Contains at least 1-1/k^2 Proportional data

4 Discrete and continuous probability density