MathBench > Environmental Science

Sampling

 

bacteriaProving Polluted Ponds

 

Here's the data from the 10 ponds, the way it was collected:

pond # type #fish
1 clean 100
2 polluted 250
3 clean 400
4 clean 300
5 polluted 100
6 clean 450
7 polluted 50
8 polluted 150
9 clean 550
10 polluted 0

 

How can you use this data to support your claim that pollution hurts fish?

First, you could take averages for the polluted vs. clean ponds. Try that now:

On average, how many fish are in the clean ponds, and how many in the polluted ponds.

(To make this problem interactive, turn on javascript!)

I think I have the answer: 360 fish in clean ponds, 110 in polluted ponds

 

So the averages make a pretty strong case that clean water is better for fish. What if you need some graphical backup? Which of these 2 graphs below would be better?