# What statistical test do I use for differences in proportions?

I have two groups of samples with a proportion of mutations in each sample being a particular type (the proportions are represented as a fraction of 1). How to I check if that type of mutation is significantly likelier to happen in one group over the other?

• You could use a $\chi^2$ test for proportions. – user25658 Sep 7 '13 at 2:09
• – Gala Sep 7 '13 at 5:06
• If you want to be able to consider both one- and two- tailed tests, what about a two-sample proportions test? – Glen_b Sep 7 '13 at 7:16