Use the following data for questions 4 and 5 The monthly high and low levels of units and total manufacturing overhead for Ratnere ompany are shown below Manufacturing Units Overhead Highest observed level Lowest observed level. 81,000 36,000 306,000 234,000 72,000 4 Refer to the above data. The cost formula for Ratnere's monthly overhead cost can be expressed as a $2.65 average cost per unit. b $1.75 average cost per unit. c $24,000 fixed cost plus $1.00 per unit. d $72,000 fixed cost+ $2.00 per unit. Refer to the above data. In a month in which 30,000 equivalent full units are produced, Ratnere's manufacturing overhead should be approximately: a $52,500 b $79,500 5 c 132,000 d S 90,500