Q1) Sample of 20 pages was taken without replacement from 1,591- page phone directory Ameritch Pages plus yellow pages.  On each page, mean area devoted to show ads was measured. (A display ad is a large block of multicoloured illustrations, maps, and text).  Data (in square millimetres) are shown below:

i) Create a 95 % confidence interval for the true mean.

ii) Why might normality be the issue here?

iii)  What sample size would be required to obtain the error of ± 10 square millimeters with 99% confidence?

iv) If this is not a reasonable requirement, suggest one that is. (Data are from a project by MBA Student Daniel R. Dalach)(Display ads)