im trying to calculate the new cost of production at the new given price and volume, and I'm using the current per unit cost times the current production volume (variable cost=4*25000/20000=5) I'm not sure if that is right, also I'm not sure if the $3 fixed cost will change along with the volume change

Given the significant impact of COVID-19 on FM12 sales, the marketing department of Bella Ltd has estimated the potential sales volumes which could be achieved at three alternative sales prices