Question 980618
p = 0.6
z = 1.96 (use a <a href="http://www.sjsu.edu/faculty/gerstman/StatPrimer/t-table.pdf">table</a> or calculator)
E = 0.04


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n = p(1-p)(z/E)^2


n = 0.6(1-0.6)(1.96/0.04)^2


n = 576.24


n = 577 ... Round up to the nearest whole number



The min sample size required is 577