46. Use the Rule of 72 to calculate the approximate number of years that it will take an investment to double, assuming that 10% can be earned annually on the investment. 47.48. Great Grocery Store, a local retail grocery store, is considering a $200,000 expenditure for new freezers in its Frozen Food Department. These freezers are expected to have a $20,000 salvage value at the end of their eight-year life. a. Based on the above information, calculate the annual Depreciation Expense for the new freezers. Assume that the straight-line depreciation method is used. b. If Great Grocery Store is in the 28% tax bracket, calculate the annual tax savings that the firm will realize due to the tax-deductibility of the non-cash Depreciation Expense on these new freezers