simpangan baku dari data 4,6,9,1

x rata-rata = 4+6+9+1/4 = 20/4 = 5
n=4
simpangan baku = √(x-xrata-rata)²/n-1 = √(4-5)²+(6-5)²+(9-5)²+(1-5)²/3
                           =√1+1+16+16/3=√34/3=√11,33=3,366
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