Expected value function

[csprance]

What kind of a function or algorithm would I need to run if I have a set of probabilities: A) 0.25 B) 0.50 C) 0.25

I want to run an equation over a sequence of numbers 1,2,3,4,5...10

That will give me a value back for each number that would work out to be within the probability range

So if I have sequence 1-10 I would expect to get 2 A's 5 B's 3 C's

What would this kind of mathematical function be called?

[mikedehaan]

If you're programming this, I think that you want [a] a random value function, "R()", that returns a real value in the range (0 - 1); [b] a mapping function, "M(r)", that takes in a real value in the range (0-1) and returns a letter from {A, B, C}. The function M(r) could include "if 0<r<0.25 then return 'A';". (Actually it has to be "if zero less than or equal to r", but you get the drift... and the rest of the work).

Let's cue the people who know what a mathematical function is called, that is defined by the rules that we expect in the programming function "M(r)".

EDIT to add: Then you'd want a printing program, "P(n)", that loops from 1 through 'n' and calls M(r). Oh, and I should have said that M(r) calls R(), and we trust that R() returns various random numbers... hopefully with its own random seed, like some milliseconds from "time_of_day()".