After Elections Were Held, It Was Desired to Estimate the Proportion

Multiple Choice

After elections were held, it was desired to estimate the proportion of voters who regretted that they did not vote. How many voters must be sampled in order to estimate the true proportion to within $2 \%$ (e.g., $\pm 0.02$ ) at the $90 \%$ confidence level? Assume that we believe this proportion lies close to $30 \%$ .

A) Cannot determine because no estimate of $\mathrm { p }$ or $\mathrm { q }$ exists in this problem.
B) $\mathrm { n } = 2017$
C) $n = 2401$
D) $n = 1421$
E) $n = 1692$