Jawabanmu

2014-04-25T19:29:47+07:00
rataan x = (7+7+8+6+7)/5 = 35/5 = 7 

ragam (varians) 
s^2 = (7-7)^2+ (7-7)^2 + (8-7)^2+ (6-7)^2+ (7-7)^2 per 5 
s^2 = (0 +0+1+1+0)/5 = 2/5 

simpangan baku 
s = V(2/5) = 2/5 V5 ~ Semoga bermanfaat ( maaf kalau salah )