Answer:
1
Explanation:
A data arranged in descending order is a data arranged from the biggest to the smallest. The medisn of the data sets is the value at the middle of the dataset after rearrangment.
For the dataset {8, x, 4,1}, the median will be x and 4. Since we have two median values, we will take their average as shown
Median(1) =
... 1
Simialrly for dataset {9, y, 5,2}, the median will be y and 5.
Median(2) =
...2
Since the medians of the two given datasets are equal, we will equate equation 1 and 2 and calculate for y-x as shown;
![(x+4)/(2) = (y+5)/(2)](https://img.qammunity.org/2021/formulas/mathematics/college/bpfj9ijmjvie36cmpbdnbknx4qcq6lrggu.png)
![x+4 = y+5\\x-y = 5-4\\x-y = 1\\y-x = -1](https://img.qammunity.org/2021/formulas/mathematics/college/ez37t0m0qh35f1m55j69fmdmh7rkrgzci0.png)
Therefore y-x = -1
(y-x)² = (-1)²
= 1