VitaminD, whether ingested as a dietary supplement or produced naturally when sunlight falls upon theskin, is essential forstrong, healthy bones. The bone disease rickets was largely eliminated during the1950s, but now there is concern that a generation of children more likely to watch TV or play computer games than spend time outdoors is at increased risk. A recent study of2300 children randomly selected found 24% of them deficient in vitamin D.

a) Construct a98% confidence interval for the true proportion of children who are deficient in vitamin D.

b) Explain carefully what the interval means.

c) Explain what"98% confidence" means.