An important issue in assessing nuclear energy is whether excess disease risks exist in the communities surrounding nuclear-power plants. A study undertaken in the community surrounding Hanford, Washington, looked at the prevalence of selected congenital malformations in the counties surrounding the nuclear-test facility. a) Suppose 28 cases of Down's syndrome are found and only 19 are expected based on Birth Defects Monitoring Program prevalence estimates in the states of Washington, Idaho, and Oregon. Are there significant excess cases in the area around the nuclear-power plant? (Round your answer to four decimal places.) There (is or is not) a significant excess of Down's syndrome cases in the area, since the probability of observing at least 28 cases is (value here) which is (small since it is less than 0.05, or not small since it is greater than 0.05). b) Suppose 11 cases of cleft palate are observed, whereas only 7 are expected based on Birth Defects Monitoring Program estimates. What is the probability of observing exactly 11 cases of cleft palate if there is no excess risk of cleft palate in the study area? (Round your answer to four decimal places.) c) Do you feel there is a meaningful excess number of cases of cleft palate in the area surrounding the nuclear-power plant? Explain. (Round your answer to four decimal places.)

There (is or is not) a significant excess of cleft palate cases in the area, since the probability of observing at least 11 cases is (value here) which is (small since it is less than 0.05, or not small since it is greater than 0.05. The probability is (a borderline case since it's less than, or not a borderline case because it's greater than) double 0.05 and therefore the result (may not be, or is definitely) meaningful.