Step 1 : arrange the 10 terms in ascending order :
{2, 3,4,5,6,7,7,8,9,11}
step 2: find the median ( this is the middle term in the arranged data set I will high light the medians )
(6+7)/2 = 13/2 = 6.5.
Step 3 : find the median in the lower half of the data set {2,3,4,5,6...} which is 4.
Step 4: find the median in the upper half of the data set {...7,7,8,9,11}
which is 8.
Now lets find our iter quartile range :
The IRQ /IQR is the difference between the first quartile (4) and the third quartile (8)= 8-4 =4
IQR = 4