Display average of trends

Discussion created by mjtaylor86 on May 22, 2012

Apologies in advance but I'm a relative Arc novice.

I have continuous numerical data which represents population trends for a number of overlapping polygons representing species ranges. I need to find a way to average these population trends across the map and display them using similar imagery and a key, to the graduated colours display you can use for a count of something like species richness, from the symbology tab in layer properties.

Can anyone think of how I might accomplish this?

So to be clear, I essentially need to do produce a map of graduated colours but that doesn't just give me an indication of the range of values or number of species, but that actually averages the trend data I have and then displays this information through graduated colours.

Apologies if that is too vague or confusing. I will try harder if it is.

Many thanks