What is the interquartile range for the numbers 4,3,2,3,5,7,2,1

First organize numbers from left to right:

1,2,2,3,3,4,5,7

Then, divide into 4 groups (Quartiles):

1,2 2,3 3,4 5,7

Q3-Q1 is interquartile range

(3+4/2) - (1+2/2) = 3.5 - 1.5

Interquartile range is 2