A company manufacturesrefrigerators at the rate of 500 units per week, and the standard cost of a material used in their manufacture for 2000 units is expected to be: 1200 kg (0.6 kg per unit) @ $1.75 per kg = 2100 During the month of February production data showed that 1800 units were produced that required 1000 kg of material and the purchase price was $1.60 per kg. a) Calculate the adjusted standard costs for production based upon this material data. b) Calculate all three of the material variances.