This might be a silly question for you guys, but I've been struggling myself to handle it. Imagine we have a fish tank with:
- number of fishes: 1000
- weighted average: 0.233 (kg)
One day, I decided to remove 200 fishes having 0,5 kg of weighted average. What would be the new weighted average and how to calculate it?
On adding operations, I handle it as follows (using the same example):
((1000 * 0.233) + (200*0.5))/(1000+200), resulting 1 kg.
Any help will be really appreciated!
Thanks!
Okay so the total weight before you removed the 200 fishes was $0.233\cdot 1000=233$ kg. The removed 200 fish have a total weight $200*0.5=100$ kg. This leaves in the box 800 fishes with a weight of 133 kg, so the average weight of the fishes inside the box is $\frac{133}{800}=0.166$ kg.