A recent poll of 500 residents in a large town found that only 36% were in favor of a proposed referendum to build a new high school.Find the margin of error for this poll if we want 90% confidence in our estimate of the percent of residents in favor of this proposed referendum.
A)3.53%
B)2.43%
C)10%
D)5%
E)7.06%

Question

Quizplus · Accepted Answer

The margin of error (ME) for a proportion can be calculated using the formula: ME = Z * sqrt[(p(1-p))/n], where Z is the Z-score corresponding to the desired confidence level, p is the sample proportion, and n is the sample size. For a 90% confidence level, the Z-score is approximately 1.645. Plugging in the values: p = 0.36, n = 500, we get ME = 1.645 * sqrt[(0.36*0.64)/500] ≈ 0.0353 or 3.53%.

A Recent Poll of 500 Residents in a Large Town