Odp.:
m X = - 1 ´ 1/3 + 0 ´ 1/3 + 1 ´ 1/3 = 0,
m Y = 0,
s 2X = (- 1- 0)2 ´ 1/3 + (0- 0)2 ´ 1/3 + (1- 0)2 ´ 1/3 = 2/3,
s 2Y = (- 2- 0)2 ´ 1/3 + (0- 0)2 ´ 1/3 + (2- 0)2 ´ 1/3 = 8/3,
s 2Y > s 2X.