Tentukan simpangan baku dari 12,14,18,15,13,17,15 dan 16

rata-rata = 120/8 = 15

¤ Ragam
S^2 = (12-15)^2 + (14-15)^2 + (18-15)^2 + (15-15)^2 + (13-15)^2 + (17-15)^2 + (15-15)^2 + (16-15)^2
= 3^2 + 1^2 + 3^2 + 0^2 + 2^2 + 2^2 + 0^2 + 1^2
= 9+1+9+0+4+4+0+1
= 28 / rata"
= 28/8
= 3,5

¤ simpangan baku = akar S^2 = akar 3,5

*)semoga membantu... ^.^