Answer:
30.5
Explanation:
Order the values
72, 83, 87, 90, 97, 104, 114, 117, 142
Now, find the middle value (the median)
Here, it is 97.
Now, find the "middle" of the lower half and upper half.
For the lower half, it's the mean of 83 and 87 = 85
For the upper half, it's the mean of 114 and 117 = 115.5
Now, find the difference between the upper and lower medians
115.5 - 85 = 30.5