뒤로A puzzle company is interested in the average number of pieces in their jigsaw puzzles, so they plan to create a confidence interval for the true mean. The easiest puzzle in their line is pieces, and the largest is pieces. Use the range rule of thumb to estimate the sample standard deviation.
A bookstore is interested in the average length of books in its adult fiction section. Find the minimum sample size required to create a confidence interval with a margin of error no more than pages if...
(A) The standard deviation is known to be about pages.
A bookstore is interested in the average length of books in its adult fiction section. Find the minimum sample size required to create a confidence interval with a margin of error no more than pages if...
(B) The standard deviation is unknown, but the longest book is pages and the shortest is pages.