Discussion:
Q: Sample of 20 pages was taken out replacement from the 1,591 page directory. On each page the main areas devoted to display ads was measured. The data is square millimeters are shown
0 260 356 403 536 0 268 369 428 536
268 396 469 536 162 238 403 536 536 130
a) Construct a 95 per cent confidence intervals for the true mean.
b) Why might normality be and issue here?
c) What size sample be needed to obtain the plus or minus 10 square millimeters with 99 percent confidence?
d) If this is not reasonable requirement suggest one that is.