Answer:
a. $77
b. $101
c.Income statement for the month using the contribution format and the variable costing method.
Sales ( $122 × 8,200)                                                                       1,000,400
Less Cost of Sales 
Opening Stock                                                                      0
Add Cost of Goods Manufactured (8,300× $77)           639,100
Less Closing stock ( 100 × $77)                                        (7,700)    (631,400)
Contribution                                                                                       369,000
Less Expenses
Fixed manufacturing overhead                                                      ($199,200)
Variable selling and administrative ($7×8,200)                                (57,400)
Fixed selling and administrative                                                    ($106,600)
Net Income / (Loss)                                                                                5,800
d.Income statement for the month using the  absorption costing method.
Sales ( $122 × 8,200)                                                                       1,000,400
Less Cost of Sales 
Opening Stock                                                                      0
Add Cost of Goods Manufactured (8,300× $101)           838,300
Less Closing stock ( 100 × $101)                                        (10,100) (828,200)
Contribution                                                                                       172,200
Less Expenses
Variable selling and administrative ($7×8,200)                                (57,400)
Fixed selling and administrative                                                    ($106,600)
Net Income / (Loss)                                                                                8,200
e.Reconcile the variable costing and absorption costing operating incomes for the month
Absorption Costing Net Profit                                                               8,200
Add Fixed Costs in Opening Stock                                                           0
Less Fixed Costs in Closing Stock (100 × $24)                                   (2,400)
Variable Costing Net Profit                                                                    5,800 
Explanation:
Product Cost (Variable Costing) = All Variable Manufacturing Costs
                                                      = $27 + $46 + $4
                                                      = $77
Product Cost (Absorption Costing) = All Variable Manufacturing Costs + All Fixed Manufacturing Costs
                                                           = $77 + ($199,200/8,300)
                                                           = $77 + $24
                                                           = $101
Income Statements
Non Manufacturing Costs are treated as a Periodic Cost in Absorption Costing Income Statement
Whilst Both Fixed Manufacturing Costs and Non Manufacturing Costs are treated as a Periodic Cost in Variable Costing Income Statement.
Reconciliation
The difference in Profit is due to Fixed Cost component absorbed in Absorption Costing.