A family friend has asked your help in analyzing the operations of three anonymous companies operating in the same service sector industry. Supply the missing data in the table below: $($Loss amounts should be indicated by a minus sign. Do not round your intermediate calculations.$)$

$\backslash$table$[[,$Company A$,$Company B$,$Company C$],[$Sales$,$$$,390,000,,$$$,840,000,,$$$,610,000,],[$Net operating income,,,,$$,49,000,,,,],[$Average operating assets,$$,164,000,,,,,$$$,155,000,],[$Return on investment $($ROI$),,20,\%,,19,\%,,,\%$