Jangkauan kuartil dari data : 2, 3, 3, 6, 7, 8, 9, 9, 11

•) Q1 = X1 (9+1):4
X = 10:4
X = 2,5
= X2+0,5(X3-X2)
= 3+0,5(3-3)
= 3+0,5.0
= 3
Jadi X3 = 3

•) Q2 = X2 (9+1):4
X = 20:4
X = 5
Jadi X5 = 7

•) Q3 = X3 (9+1):4
X = 30:4
X = 7,5
= X7+0,5(X8-X7)
= 9+0,5(9-9)
= 9+0,5.0
= 9
Jadi X9 = 11

(Maaf jika salah)