Normally i always advice everyone to use python. In this case, i advicr you to trad the gaussian theory and to use a pen and calculate it without computer after that you can figure out the formula then use excel for graphics and python for software. I have calculate the normal distribution for the number of primes in each consequetive 100 numbers like 25 21 16 16 17.. then the frequeny of 25 21 16 17.. 25...0 i got 25->1 21->1 16->6 i used 30 million natural numbers and got the data with java and the graphic with excel.. in 2010