statistics
posted by Koia on .
A researcher conducted a study of the access speed of 40 hard drives and concluded that his
maximum error of estimate was 15. If he were to conduct a second study to reduce the
maximum error of estimate to 5, about how many hard drives should he include in his new
sample?

SEm = SD/√n
15 = SD/√40 (Calculate SD and insert below.)
5 = SD/√? 
A researcher conducted a study of the access speed of 35 hard drives and concluded that his maximum error of estimate was 35. If he were to conduct a second study to reduce the maximum error of estimate to 7, about how many hard drives should he include in his new sample?