A poll in one country indicated that 53% favor imposing the death penalty (the c
ID: 3075109 • Letter: A
Question
A poll in one country indicated that 53% favor imposing the death penalty (the country currently does not have it). The poll did not report the sample size but stated, "Polls of this size are considered to be accurate to within 2.3 percentage points 90% of the time." About how large was the sample size? Click here to view page 1 of the standard normal cumulative probabilities table. LOADING... Click here to view page 2 of the standard normal cumulative probabilities table. LOADING... About how large was the sample size? nequals nothing (Round up to the nearest integer.)
Explanation / Answer
p = 0.53
Z for 90% confidence interval = Z0.05 = 1.645
Margin of error = 0.023
or, Z0.05 * sqrt(p * (1 - p) / n) = 0.023
or, 1.645 * sqrt(0.53 * 0.47 / n) = 0.023
or, n = 1274.2 or 1274 (ans)