simpanan baku dari data 7 8 6 9 6 8 5

rata2 : 7+8+6+9+6+8+5 : 7
49 : 7 = 7
ragam = (7-7)²+(8-7)²+(6-7)²+(9-7)²+(6-7)²+(5-7)²+(5-7)² / 7
= 0 + 1 + 1 + 4 + 1 + 4 + 4 / 7
= 15/7
simpangan baku = √ragam = √15/7