A stationery store wants to estimate 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 a standard deviation of $0.44.
a. Is there evidence that the population mean retail value of the greeting cards is different from $2.50? (Use a 0.05 level of significance.)
b. Determine the /7-value and interpret its meaning.