# Question

A sample of 20 pages was taken from a Yellow Pages directory. On each page, the mean area devoted to display ads was measured (a display ad is a large block of multicolored illustrations, maps, and text). The data (in square millimeters) are shown below:

(a) Construct a 95 percent confidence interval for the true mean.

(b) What sample size would be needed to obtain an error of ±20 square millimeters with 95 percent confidence? (Data DisplayAds are based on a project by MBA student Daniel R. Dalach.)

(a) Construct a 95 percent confidence interval for the true mean.

(b) What sample size would be needed to obtain an error of ±20 square millimeters with 95 percent confidence? (Data DisplayAds are based on a project by MBA student Daniel R. Dalach.)

## Answer to relevant Questions

8.67 Sixteen owners of 2010 Audi A4 sedans kept track of their average fuel economy for a month. The results are shown below. (a) Construct a 95 percent confidence interval for the mean. (b) What factor(s) limit the ...A pediatrician's records showed the mean height of a random sample of 25 girls at age 12 months to be 29.530 inches with a standard deviation of 1.0953 inches. (a) Construct a 95 percent confidence interval for the true mean ...A study showed that fourteen of 180 publicly traded business services companies failed a test for compliance with Sarbanes-Oxley requirements for financial records and fraud protection. Assuming that these are a random ...Biting an unpopped kernel of popcorn hurts! As an experiment, a self-confessed connoisseur of cheap popcorn carefully counted 773 kernels and put them in a popper. After popping, the unpopped kernels were counted. There were ...If you repeated a hypothesis test 1,000 times (in other words, 1,000 different samples from the same population), how many times would you expect to commit a Type I error, assuming the null hypothesis were true, if (a) α = ...Post your question

0