Question 927121
a) p = 33/150 = .22
ME = 2.576sqrt((.22*.78)/150) = .034
CI: .22 ± .034
..........
b) n = .22*.78(2.576/.03)^2 = 1265.2  0r 1266 (next whole number)
......
c) If no estimate of the proportion is available, how large should the sample be. 
Larger the sample, smaller the ME is. Use Your own parameters.