Hitunglah simpangan rata rata, ragam dan simpangan baku dari data 12 11 9 8 9 10 9 12 ?

*)rata" = (12+11+9+8+9+10+9+12) / 8
= 80/8
= 10

*)ragam
S^2 = ((12-10)^2 + (11-10)^2 + (10-9)^2 + (10-8)^2 + (10-9)^2 + (10-10)^2 + (10-9)^2 + (12-10)^2) / 8
= (2^2 + 1^2 + 1^2 + 2^2 + 1^2 + 0 + 1^2 + 2^2) / 8
= (4+1+1+4+1+0+1+4) / 8
= 16/8
= 2

*)simpangan baku
S = √(S^2) = √(2)

semoga membantu ^.^