A market research firm has been engaged to do a study of dishwashing detergents preferred by homemakers in San Francisco 800,000 population) as compared to those preferred in New York 8,000,000 population).In order to obtain results of about equal reliability in each city, the number of homemakers polled in New York should be
A)ten times the number polled in San Francisco.
B)10 or 3.16 times the number polled in San Francisco.
C)about the same as in San Francisco.
D)half the number polled in San Francisco.

Question

Quizplus · Accepted Answer

The reliability of results in surveys like this is more dependent on the sample size relative to the variability of the population's preferences than on the total population size. Therefore, as long as the sample sizes are large enough to accurately reflect the populations' preferences, the number of homemakers polled in each city should be about the same to achieve results of equal reliability.

A Market Research Firm Has Been Engaged to Do a Study