Ggr 270 lecture 9 november 10, 2010. To determine the level of precision of estimates, a confidence interval is placed around the sample. a properly created sample is essential for the successful application of inferential statistics. often, geographers want to know if a particular sample is representative of the population. Issue here may be to show that the sample differs significantly from the population. reject h0 as false, when in fact it is true. observing a difference when none actually exists. Fail to reject h0 when in fact it is false. Failing to observe a difference when one does exist. Test used is a function of the research question, and research assumptions. Tests will vary according to the number of samples drawn, sampling design, scale of information. one of the most com mon is the one-sample means test or one-sample difference of means test. placing a probability statement on the likelihood of sample error.