Inferential Statistics - R, Python or Extension

As a partner, I am looking to use RapidMiner to integrate related inferential statistical methods such as hypothesis testing, confidence intervals, chi-square, etc. as part of a client implementation. I see there is a pay-for extension to do this work, but given the simplicity of these methods and unwanted burden of managing a paid for subscription to integrate these methods for only occasional use, is there a no-charge library of operators available, or do I need to just leverage R or Python and create my own? We only need a few methods for occasional use and I'd like to know if there are other options besides R, Python or the pay-for extension? Thanks!