The following data pertain to activity and costs for two months: July 20,000 Activity level in units Variable costs Fixed costs Mixed costs Total costs June 10,000 $20,000 15,000 10.000 $45.000 $70,000 Assuming that these activity levels are within the relevant range, what were the mixed costs for July? $10,000. $40,000 $15.000. $35.000