1. With domestic sources of building supplies running low several years ago, roughly 60,000 homes were built with imported Chinese drywall. According to an article federal investigators identified a strong association between chemicals in the drywall and electrical problems, and there is also strong evidence of respiratory difficulties due to the emission of hydrogen sulfide gas. An extensive examination of57homes found that47had such problems. Suppose these57were randomly sampled from the population of all homes having Chinese drywall.

a) Calculate the test statistic and determine theP-value.

b) Calculate a lower confidence bound using a confidence level of 99% for the percentage of all such homes that have

electrical/environmental problems. (Round your answer to one decimal place.)

c) If it is actually the case that 80% of all such homes have problems, how likely is it that the test of (a) would not conclude that more than

50% do? (Round your answer to four decimal places.)