The following data pertain to activity and costs for two months: November 10,000 October Activity level in units 5,000 Nariable costs $10,000 Fixed costs 30,000 Mixed costs 20,000 Total costs $60,000 $75,000 Assuming that these activity levels are within the relevant range, what were the mixed costs for November? $25,000 $35,000. $40,000. $20,000