Answer:
The Journal entry is as follows:
Depletion expense - Coal Deposit A/c Dr. $280,000
To Accumulated depletion -Coal Deposit $280,000
(To record the depletion expense for the current year)
Workings:
Depletion per ton = (cost - Salvage) ÷ Total units of production
= ($900,000 - $100,000) ÷ 200,000
= $4 per ton
Depletion expense = Tonnage tons mined current year × Depletion per ton
= 70,000 tons × $4
= $280,000