simpangan baku dari data 9, 8, 7, 6, 5, adalah

jawab
statistik

xi = 9,8,7,6,5
∑xi = 35
n = 5
X = 7
s² = ∑(X-xi)²/n
s² = 1/8 [(9-7)²+ (8-7)²+ (7-7)²+(6-7)²+(5-7)² ]
s² = 1/8 [10] = 5/4
simpangan baku = √s²   =  √(5/4) = 1/2 √5