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.