A small company hoats its building and will spend $9.720 in year 1 on natural gas for this purpose, Cost increases of natural gas are expected to be 8% per year starting year 2. Thoir maintenance on the gas tumace is going to be $396.75 in the first year and this expense is expected to increase by 15% per year starting year 2. If the planning horizon is 13 years what is the total annual equivalent expense for operating and maintaining the furaco? The interest rate is 18% per year. (a) The total present worth of operating and maintaining the turnace is $||)(Round to nearest dolar) (b) The total annual equivalent experto for operating and maintaining the tumace is $11. (Round to nearest dollar)