Nation Standard Newspaper poll for the year 2004 presidential campaign in
U.S sampled 491 potential voters in October 2004. A primary purpose of
the poll was to obtain an estimate of the proportion of potential voters who
favour each candidate. Closer to December 2004 elections, better precision
and smaller margins for error were desired. Assume a planning value for the
population proportion of p = 0.50 and that a 95% confidence level is desired.
Required:
Determine the recommended sample size for each of the following surveys:
Survey Margin of
error
Early December 0.02
Pre-election day 0.01
(15 marks)