1The local paper wants to estimate the proportion of all eli

1)The local paper wants to estimate the proportion of all eligable voters that are undecided in the mayoral election. Find the minimum sample size required to estimate this proportion with desired margin of error of 0.04 and confidence level of 95%. There are no prior estimates of p and q.

2)consider problem \"1\", and suppose the paper uses results from a prior poll suggesting that 14% of all voters are undecided. Find the minimum sample size required to estimate the proportion of all eligable voters that are undecided with desired margin of error of 0.04 and confidence level of 99%

Solution

a)
Compute Sample Size ( n ) = n=(Z/E)^2*p*(1-p)
Z a/2 at 0.05 is = 1.96
Samle Proportion = 0.5
ME = 0.04
n = ( 1.96 / 0.04 )^2 * 0.5*0.5
= 600.25 ~ 601

b)
Compute Sample Size ( n ) = n=(Z/E)^2*p*(1-p)
Z a/2 at 0.05 is = 1.96
Samle Proportion = 0.14
ME = 0.04
n = ( 1.96 / 0.04 )^2 * 0.14*0.86
= 289.0804 ~ 290