A stationary store desires to determine the mean retail value of greeting cards that it has in its inventory. A random sample of 100 greeting cards indicates a mean value of $2.55 and standrard deviation of $0.44
a. Supposing a noraml distribiton, Make a 95% confidence interval esimate for the mean value of all greeting cards in store's inventroy.
b. Assume there were 2500 greeting cards in the store's inventory. How are the results in (a) useful in assisting the store owner to Determine the total value of the inventory?