Question

1. If you were a campaign worker and wanted to estimate the percentage of eligible voters who recognize your candidate’s name, how many people should you survey? Assume that you want to be 90% confident that the sample percentage is in error by no more than two percentage points. First, what formula or test would you use to determine that number?

   	A.	1-PropZTest
   	B.
   	C.
   	D.

QUESTION 16

1. If you were a campaign worker and wanted to estimate the percentage of eligible voters who recognize your candidate’s name, how many people should you survey? Assume that you want to be 90% confident that the sample percentage is in error by no more than two percentage points. Calculate that number.

Answer 1

The following information is provided,
Significance Level, α = 0.1, Margin of Error, E = 0.02

The provided estimate of proportion p is, p = 0.5
The critical value for significance level, α = 0.1 is 1.64.

The following formula is used to compute the minimum sample size required to estimate the population proportion p within the required margin of error:
n >= p*(1-p)*(zc/E)^2
n = 0.5*(1 - 0.5)*(1.64/0.02)^2
n = 1681

Therefore, the sample size needed to satisfy the condition n >= 1681 and it must be an integer number, we conclude that the minimum required sample size is n = 1681
Ans : Sample size, n = 1681