Help solving and I would like to know how the percentage for S2 and S1 is determined. Thank you.

Blustar Company has two service departments, Administration and Accounting, and two operating departments, Domestic and International. Administration costs are allocated on the basis of employees, and Accounting costs are allocated on the basis of number of transactions. A summary of Blustar operations follows: Administration Accounting Domestic International Employees 25 15 60 50,000 10,000 40,000 Transactions $62,000 Department direct costs $27,000 $154,500 $592,000 Blustar estimates that the cost structure in its operations is as follows: Administration Accounting Domestic International Variable costs 5,000 26,000 $111,000 $437,000 155,000 36.000 22,000 43.500 Fixed costs 62,000 $27,000 $154,500 $592,000 Total costs 10.250 5,000 Avoidable fixed costs 18,000 $110,000 Required a. If Blustar outsources the Administration Department, what is the maximum it can pay an outside vendor without increasing total costs? (Do not round intermediate calculations.) Maximum amount