The article "Genetically Based Tolerance to Endosulfan, Chromium (VI) and Fluoranthene in the Grass Shrimp Palaemonetes pugio" (R. Harper- Arabie, Ph.D. Thesis, Colorado School of Mines, 2002) reported that out of 1985 eggs produced by shrimp at the Diesel Creek site in Charleston, South Carolina, 1919 hatched, and at the Shipyard Creed site, also in Charleston, 4561 out of 4988 eggs hatched. Find a 99% confidence interval for the difference between the proportions of eggs that hatch at the two sites?