A researcher conducted a study of the access speed of 50 har

A researcher conducted a study of the access speed of 50 hard drives and concluded that his maximum error of estimate was 30. If he were to conduct a second study to reduce the maximum error of estimate to 6, about how many hard drives should he include in his new sample?

Solution

Note that the sample size is inversely proportional to the square of the margin of error.

Thus, the new sample size will be

n = 50*(30^2/6^2) = 1250 [ANSWER]