Given info:

Order Entry Expenses = $800,000

Manual Orders = 16,000

EDI orders = 8,000

Order Lines = 150,000

Question: How do I calculate the activity cost-driver rate for manual orders, EDI orders and order lines?

An example on couse hearo suggests that Manual orders = 20%, Order Lines = 75% and EDI orders = 5%.

How do I go about calculating the percentages as noted above? I know how to get the per unit cost, but how to get the percentage confuses me.