Moments of a distribution
Descriptive statistics · Mathematics
Study notes
Q: Find the first two moments (about origin) of: 1, 2, 3, 4. First moment (r=1): (1+2+3+4)/4 = 10/4 = 2.5 = mean! Second moment (r=2): (1+4+9+16)/4 = 30/4 = 7.5. Variance = 2nd moment about mean = 7.5 - 2.5^2 = 7.5 - 6.25 = 1.25.