In a randomized controlled trial, insecticide-treated bednets were tested as a way to reduce malaria. Among 302 infants using bednets, 13 developed malaria. Among 279 infants not using bednets, 30 developed malaria. Use a 0.05 significance level to test the claim that the incidence of malaria is lower for infants using bednets. a. Test the claim using a hypothesis test. b. Test the claim by constructing an appropriate confidence interval. c. Based on the results, do the bednets appear to be effective?