Question: In Stearns County, Minnesota, it was found that 15 of 27 houses sampled had radon concentrations exceeding 4 pCi/l. In neighboring Wright county, a sample of 14 houses found 9 with radon concentrations over 4 pCi/l. Test the hypothesis that the proportion of houses in Stearns County with radon levels over 4 pCi/l is the same as the proportion for Wright County.