nilai simpangan kuartil dari data 4,4,5,5,6,7,7,8,8

Q1= x1/4 (n+1)
=x1/4 (9+1)
=x1/4. 10
=x2,5
=4,5

Q3 = x3/4. (n+1)
=x3/4. (9+1)
=x3/4. 10
=x7,5
=7,5

Qd= 1/2 (Q3-Q1)
=1/2 (7,5-4,5)
=1/2 (3)
=1,5