Comparative data on three companies in the same service industry are given below. Required: $2.$ Fill in the missing information. $($Round the "Turnover" and "ROI" answers to $2$ decimal places.$)$ Company A B C Sales $$2,688,000$ $$1,380,000$ C$?$ Net operating income $$510,720$ $$207,000$ C$?$ Average operating assets $$1,680,000$ B$?$ $$3,450,000$ Margin A$?\%$ B$?\%5\%$ Turnover A$?$ B$?1\mathrm{.}90$ Return on investment $($ROI$)$ A$?\%6\mathrm{.}00\%$ C$?\%$