1 You want to obtain a sample to estimate a population propo

1. You want to obtain a sample to estimate a population proportion. Based on previous evidence, you believe the population proportion is approximately p*=71%. You would like to be 99.9% confident that you estimate is within 3% of the true population proportion. How large of a sample size is required?

n =

B. You want to obtain a sample to estimate a population proportion. At this point in time, you have no reasonable estimate for the population proportion. Your would like to be 99% confident that you estimate is within 0.1% of the true population proportion. How large of a sample size is required?

n =

Solution

1)
Compute Sample Size ( n ) = n=(Z/E)^2*p*(1-p)
Z a/2 at 0.001 is = 3.29
Samle Proportion = 0.71
ME = 0.03
n = ( 3.29 / 0.03 )^2 * 0.71*0.29
= 2476.3135 ~ 2477

2)
Compute Sample Size ( n ) = n=(Z/E)^2*p*(1-p)
Z a/2 at 0.01 is = 2.58
Samle Proportion = 0.5
ME = 0.001
n = ( 2.58 / 0.001 )^2 * 0.5*0.5
= 1664100 ~ 1664100