Discussion:
Radon is a gas produced when radium decays, and it can enter homes where it can become a health threat.
Among 186 homes in Hyde Park, New York (home of Franklin D. Roosevelt), 16% were found to have unsafe radon levels (above 4 picocurries per liter). Among 237 homes in LaGrange, New York (home of the author), 19% were found to have unsafe radon levels (based on data from the New York State Department of Health).
Use a 0.05 significance level to test the claim that two Dutchess County regions have different rates of unsafe radon levels. Does the presence of unsafe radon levels appear to vary by region?