8. Elena is ready to calculate the net present value of buying the shuttle bus. If it is greater than the cost of the net present value of leasing, cell B22 displays the recommendation "BUY"; otherwise, cell B22 displays the recommendation "LEASE". Elena has already calculated the initial investment amount (cell F3) as the current price, plus the cost of a service contract, plus the tax on the sale. In cell B20, enter a formula that adds the initial investment amount of buying the shuttle bus (cell F3) to the result of the NPV function. In the NPV function, use the monthly discount rate (cell B19) as the rate of return and the Buy Scenario values for months 136 and the ending value (range F4:F40) as the cash flows for owning and using the shuttle bus.