Refer to Example 5.9. Later in the potato growing season, it takes more time to inspect stems. Suppose that it takes two minutes to inspect each stem. Which psu size is most efficient?

Repeat Exercise 8 for the purchase cost for each book. Plot the data, and estimate the total and average amount she has spent for books, along with the standard errors. A homeowner with a large library needs to estimate the purchase cost and replacement value of the book collection for insurance purposes. She has 44 shelves containing books, and selects 12 shelves at random. To prepare for the second stage of sampling, she counts the number of books Mi, on the selected shelves. She generates five random numbers between 1 and Mi for each selected shelf, to determine which specific books, numbered from left to right, to examine more closely. She then looks up the replacement value for the sampled books in Books in Print. The data are given in the file books.dat.

1. Draw side-by-side boxplots for the replacement costs of books on each shelf.

Does it appear that the means are about the same? The variances?

2. Estimate the total replacement cost for the library, and find the standard error of your estimate. What is the estimated coefficient of variation?

3 .Estimate the average replacement cost per book, along with the standard error.

Compute the estimated coefficient of variation?