# Water Quality Index equation and math help

#### Forsythe

Water Quality Index equation and math help!!!

Hi there,

I am an arts student who, due to signing up for classes very late in the semester, has been stuck with an environmental sciences course. This course was just fine until I got our final assignment, which is a Water Quality Index lab. The math in it is just plain scary. Not only do I not have the background to do this, but I have not done any form of mathematics since I was 17 and in highschool. I have posted the equation and data given to me in class. Can anyone help me? (the assignment is due tomorrow).

This is the equation we were given:

http://photos-e.ak.fbcdn.net/hphotos-ak-snc1/hs031.snc1/2588_78647385785_530460785_2906212_1687336_n.jpg [Broken]

Where:

SVi is Sensitivity Value of the ith taxon
Xi is the density of the ith taxon
n is the number of taxa in the sample
1n is the natural logarithm
e is the number 2.718

Values:

Quantitative sample: (two Surber samples combined) (first listed is # in samples, second is sensitivity)

Eph., 43, 3
Hep., 25, 3
Per., 3, 4
Perlo, 5, 4
Cap, 1, 4
Cor, 6, 2
Tip, 16, 2
Emp, 3, 2
Chir, 80, 2
Hyd, 38, 3
Rhy, 1, 4
Pol, 2, 2
Lim, 1, 2

Quantitative sample: (two Surber samples combined) (first #= number in samples, second = sensitivity) (I think this was the one that we actually collected in the lab)

Eph 43, 3
Per, 3, 4
Cor, 6, 2
Tip, 14, 2
Emp, 3, 2
Hyd, 26, 3
Rhy, 1, 4

Does anyone have any idea what these numbers mean (god I feel like I am on Lost or something)? If not, anyone know where I could possibly find people who do?

Thanks a lot guys.

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