What is the percentage area of 2.6 standard deviation

Please try to be more specific.  What I think you meant was "what is the area under the standard normal curve to the left of 2.6 standard deviations above the mean?"  If that's it, the area can be found from a table of z-scores (look for z=2.6) or by using a calculator:

normalcdf(-100,2.6) = 0.995.