The following data pertain to the Whalen Division of Northern Industries. Year 1 .....Year 2 Sales.........................................................300,000...........600,000 stockholders equity........................................38,000...........400,000 Average operating assets...............................?............................? Turnover.....................................................6.............................1.2 Return on investment................................?............................9.6% Minimin required rate of return.................?............................7% Redidual income .................................16,000..........................? The margin at Whalen was exactly the same in Year 2 as it was in Year 1. The average operating assets for Year 2 amounted to