First we must convert these mixed numbers to improper fractions:


So then we need the product of these two numbers. That means to multiply:

But then we need the value of half of this product. So then let's multiply by one-half:

Then we can convert this from an improper fraction to a mixed number:

And so this number is half of the product of the initial two numbers.
Answer:
14km
Explanation
11km + 11km = 22km is the sum of both the width.
If you want to find the length than minus the perimeter with 22.
50km - 22km = 28km is the sum of both the length.
To know only one side of the length, divide it by 2.
28km/2 = 14km is the length
Mean = $52
median = $53
no mode
range = 63 - 40 = $23