I wonder how can I guess things. It is little complicated.
For example;
An archer makes 6 hits in 10 shots 3 hits in 17 shots and x hits in 20 shots
It's like a program which guesses a football match results with looking statistics.But what I'm trying to do is much simpler. There're just 2 variables and program trying to guess next number with looking others.
The statistical technique you're looking for is regression analysis. Either polynomial or linear depending on the type of relationship between the independent and dependent variables.
Regression analysis is not necessarily a simple topic.