Why we use 19% , instead of 20%? Please provide more detail information about it. Thank you.

Depreciation and accounting cash flow A firm in the third year of depreciating its only asset, which originally cost $194,000 and has a 5-year MACRS recovery period , has gathered the following data relative to the current year's operations: Accruals $15,600 Current assets 122,000 Interest expense 14,800 Sales revenue 422,000 Inventory 67,800 Depreciation = Costx Percentage. Therefore, Depreciation = $194,000 X. 19 = $36,860. The taxes were calculated using the following formula