A publisher wishes to know what percent of book pages will need graphics editing. a random sample of 25 pages in a textbook finds that 58% of the pages had drawings or figres on them. The standard deviation for this is 9.9 %. If the publisher wishes to reduce the standard deviation to 3.3 percent, how many pages should the publisher sample?
2006-12-22 07:32:22 · 2 answers · asked by Eugene D 1 in Science & Mathematics ➔ Mathematics
36 pages
2006-12-22 07:35:06 · answer #1 · answered by Anonymous · 0⤊ 1⤋
To reduce the standard deviation to 3.3% the publisher needs to sample an additional 200 pages, taking care to ensure that none of them has a drawing before being included in the sample. This is known as a sorted distribution, or cheating.
The standard deviation of a distribution is generally independent of the size of the sample, within the limits of probable error. This difference in standard deviations is well outside any usual probable error.
2006-12-22 16:27:45 · answer #2 · answered by Helmut 7 · 0⤊ 0⤋