A jewelry firm buys semiprecious stones to make bracelets and rings. The supplier quotes a price of $8.10 per stone for quantities of 600 stones or more, $8.50 per stone for orders of 400 to 599 stones, and $9.00 per stone for lesser quantities. The jewelry firm operates 110 days per year. Usage rate is 28 stones per day, and ordering costs are $48. a. If carrying costs are $2 per year for each stone, find the order quantity that will minimize total
annual cost.
b. If annual carrying costs are 30 percent of unit cost, what is the optimal order size?
c. If lead time is six working days, at what point should the company reorder?

Rate of return douglas keel, a financial analyst for orange industries, wishes to estimate the rate of return for two similar-risk investments, x and y. douglas's research indicates that the immediate past returns will serve as reasonable estimates of future returns. a year earlier, investment x had a market value of $27 comma 000; and investment y had a market value of $46 comma 000. during the year, investment x generated cash flow of $2 comma 025 and investment y generated cash flow of $ 6 comma 770. the current market values of investments x and y are $28 comma 582 and $46 comma 000, respectively. a. calculate the expected rate of return on investments x and y using the most recent year's data. b. assuming that the two investments are equally risky, which one should douglas recommend? why?