The units of Manganese Plus available for sale during the year were as follows: Mar. 1 June 16 Nov. 28 Inventory Purchase Purchase 20 units 29 units 41 units 90 units $30 @ $35 @ $36 $600 1,015 1,476 $3,091 There are 16 units of the product in the physical Inventory at November 30. The periodic inventory system is used. Determine the difference in gross profit between the LIFO and FIFO inventory cost systems. Enter the answer as a positive number. Determine the amount to be added to Allowance for Doubtful Accounts in each of the following cases and indicate the ending balance in each case. (a) Credit balance of $460 in Allowance for Doubtful Accounts just prior to adjustment. Analysis of Accounts Receivable indicates uncollectible receivables of $7,680. Amount added: $ Ending balance: (b) Credit balance of $460 in Allowance for Doubtful Accounts just prior to adjustment. Uncollectible receivables are estimated at 2% of credit sales, which totaled $894,000 for the year. Amount added: $ Ending balance: An asset was purchased for $64,000 and originally estimated to have a useful life of 10 years with a residual value of $3,100. After two years of straight-line depreciation, it was determined that the remaining useful life of the asset was only 2 years with a residual value of $1,240 a) Determine the amount of the annual depreciation for the first two years. b) Determine the book value at the end of Year 2 c) Determine the depreciation expense for each of the remaining years after revision