Carla Vista's Hot Dog Stand has had the following average results for the past several months: Its selling price per hot dog is $4. Total inonthly sales revenues have been $7,680, variable product costs have been $2,880 per month, variable period costs have been $480 per month, and fixed costs have been at $2,160 per month. Carla Vista's expects to have a $432 per month increase in fixed period costs beginning next month. (a) What was the operating income for the past several months with the given information? Operating income Attempts: 0 of 1 used (b) The parts of this question must be completed in order. This part will be avallable when you complete the part above