Three-circle, red-on-white is one distinctive pattern painted on ceramic vessels of the Anasazi period found at the Wind Mountain archaeological site. At one excavation, a sample of 160potsherds...

Three-circle, red-on-white is one distinctive pattern painted on ceramic vessels of the Anasazi period found at the Wind Mountain archaeological site. At one excavation, a sample of 160potsherds indicated that 70 were of the three-circle, red-on-white pattern. How many ceramic potsherds must be found and identified if we are to be 95% confident that the sample proportion p̂ of such potsherds is within 5.0% of the population proportion of three-circle, red-on-white patterns found at this excavation site? (Round your answer up to the nearest whole number.)