Answer:
Total cost= 1,266 + 0.925*hour
Step-by-step explanation:
Giving the following information: 
Month Expense Hours 
1 $2,625 1,499 
2 2,670 1,590 
3 2,720 1,605 
4 2,822 1,655 
5 2,855 1,775 
6 3,005 1,880 
7 $2,865 1,785
8 2,905 1,805 
9 2,780 1,695 
10 2,570 1,410 
11 2,590 1,550 
12 2,890 1,405 
To determine the total cost formula under the high-low method, we need to use the following formulas:
Variable cost per unit= (Highest activity cost - Lowest activity cost)/ (Highest activity units - Lowest activity units)
Variable cost per unit= (3,005 - 2,570) - (1,880 - 1,410)
Variable cost per unit= $0.925
Fixed costs= Highest activity cost - (Variable cost per unit * HAU)
Fixed costs= 3,005 - (0.925*1,880)
Fixed costs= $1,266
Fixed costs= LAC - (Variable cost per unit* LAU)
Fixed costs= 2,570 - (0.925*1,410)
Fixed costs= 1,266
Total cost= 1,266 + 0.925*hour