Porter Resources Company acquired a tract of land containing an extractable natural resource. Porter is required by its purchase contract to restore the land to a condition suitable for recreational use after it has extracted the natural resource. Geological surveys estimate that the recoverable reserves will be 2,500,000 tons, and that the land will have a value of $1,000,000 after restoration.
Relevant cost information follows:
Land $7,500,000
Estimated restoration costs 1,500,000
If Porter maintains no inventories of extracted material, what should be the charge to depletion expense per ton of extracted material?

You are thinking of making your mansion more energy efficient by replacing some of the light bulbs with compact fluorescent bulbs, and insulating part or all of your exterior walls. each compact fluorescent light bulb costs $4 and saves you an average of $2 per year in energy costs, and each square foot of wall insulation costs $1 and saves you an average of $0.20 per year in energy costs.† your mansion has 150 light fittings and 3000 sq ft of uninsulated exterior wall. to impress your friends, you would like to spend as much as possible, but save no more than $750 per year in energy costs (you are proud of your large utility bills). how many compact fluorescent light bulbs and how many square feet of insulation should you purchase? how much will you save in energy costs per year? (if an answer does not exist, enter dne.)

Arnold rossiter is a 40-year-old employee of the barrington company who will retire at age 60 and expects to live to age 75. the firm has promised a retirement income of $20,000 at the end of each year following retirement until death. the firm's pension fund is expected to earn 7 percent annually on its assets and the firm uses 7% to discount pension benefits. what is barrington's annual pension contribution to the nearest dollar for mr. rossiter? (assume certainty and end-of-year cash flows.)

Consider two similar industries, portal crane manufacturing (pcm) and forklift manufacturing (flm). the pcm industry has exactly three incumbents with annual sales of $800 million, $200 million and $100 million, respectively. the flm industry has also exactly three incumbents, with annual sales of $500 million, $450 million and $400 million, respectively. which industry is more likely to experience a higher level of rivalry?