Estimating a probability given other probabilities from a prior

Question

I have a bunch of data coming in (calls to an automated callcenter) about whether or not a person buys a particular product, 1 for buy, 0 for not buy.

I want to use this

Answer 1

Sounds like what you're trying to do is Association Rule Learning. I don't have time right now to provide you with any code, but I will point you in the direction of WEKA which is a fantastic open source data mining toolkit for Java. You should find plenty of interesting things there that will help you solve your problem.