A pizza shop owner wishes to find the 95% confidence interval of the true mean cost of a large plain pizza. How large should the sample be if she wishes to be accurate to within $0.15? A previous study showed that the standard deviation of the price was $0.26.
WHY would a pizza shop owner wish to find "THE 95% CONFIDENCE INTERVAL OF THE TRUE MEAN..."
Other than a retired Statistician who chose to open a pizza shop, would a pizza shop owner even know what a "95% confidence interval" mean???
I DOUBT IT!!!