Grandma Gertrude's Chocolates, a family owned business, has an opportunity to supply its product for distribution through a large coffee house chain. However, the coffee house chain has certain specifications regarding cacao content as it wishes to advertise the health benefits (antioxidants) of the chocolate products it sells. Past data indicate a standard deviation of 4%. If quality control inspectors wish to estimate the % cacao to within 1% of the true mean with 95% confidence, how many pieces of chocolate should they sample?