Probability of random numbers

[Soccer boy]

i am currently working with a some rainfall data and am trying to give a
somewhat probable forecast. i have data for the past 100 years, which gives
me my Average Annual rainfall, and based off of that i can get my standard
Deviation/bell curve. What i want to do is be able to generate random
numbers based off of its probability of happening. Is there a way i can do
this?

 

[Mike Middleton]

Soccer boy -

If the data are approximately normally distributed (bell-shaped histogram),
you could use
=NORMINV(RAND(),mean,stdev)

If the data are not normally distributed, or if you don't want dynamic
values, post again with more details.

- Mike Middleton
http://www.DecisionToolworks.com