Hey there! I'm happy to help!
First, we arrange the numbers from least to greatest.
26,29,31,31,32,37,43
The median here is 31 because it is the middle number. The three numbers before it is one half of it and the last 3 numbers are their own half, because you cannot split the 31 between the two halves.
Now, we want to find the first quartile. This is basically the media of the first half of numbers. So, our first half consists of 26,29, and 31.
The middle number of this first half is 29.
So, our Q1 (first quartile) is 29.
Now, for the third quartile. We do the exact same thing here but with the second half.
32,37,43
Looking at this, our Q3 is 37
The interquartile range is how far apart Q1 and Q3 are, so to find it, we subtract our Q1 from the Q3.
37-29=48
Therefore, our IQR is 8.
Congratulations! Now you can find the IQR of a data set! Have a wonderful day! :D