Hi there!
We have the numbers:
79 85 98 125 140
From the data, we can see that '98' is the median value as it is exactly in the middle. We can then split the data into equal groups on both sides of the median.
79 85
125 140
Since there are only two numbers, we can find the median of EACH sub-group (Q1 and Q3 respectively) by taking the average.
Q1 = (79 + 85)/2 = 82
Q3 = (140 + 125)/2 = 132.5
The IQR is simply the difference between Q3 and Q1, so:
IQR = 132.5 - 82 = 50.5
