Question 981166
z = 1.96 is the critical value at 95% confidence
E = 5% = 0.05 is the margin of error
Since we don't know p, we make the conservative estimate that p = 0.5



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


n = 0.5(1-0.5)(1.96/0.05)^2


n = 384.16


n = 385 ... Round up to the nearest whole number.


The min sample size needed is 385.