D1,..,d9 = 0,0,2,2,2,3,4,6,8 //there are 9 values, in ascending order Q2 (median) = d5 = 2 //value in the middle Q1 = (d2+d3) / 2 = (0+2)/2 = 1 (Q1 is middle value of d1,d2,d3,d4, but there is no middle element among four elements, that is why arithmetic mean is taken) Q3 = (d7+d8) / 2 = (4+6)/2 = 5 interquantlie range = IQR = Q3 - Q1 = 5 -1 = 4 answer: 4