SOLUTION: For a test market, find the sample size needed to estimate the true proportion of consumers satisfied with a certain new product within ±0.04 at the 90 percent confidence level, a

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Question 1171704: For a test market, find the sample size needed to estimate the true proportion of consumers satisfied with a certain new product within ±0.04 at the 90 percent confidence level, assume you have no strong feeling about what the proportion is
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
the half-interval is z(0.95)*sqrt(p(1-p)/n)
z is 1.645
p=0.5
1.645*sqrt(0.25/n)=0.04
sqrt(0.25/n)=0.0243
square both sides
0.25/n=0.00059127
n=422.81 round to 423.