Canella Foods prepares premade meals for busy executives. The budgeted cost of food prep labour is $15 per hour, and the company budgets 10 minutes per meal. Consider the following information: Labour Cost Variance $840 U Labour Quantity Variance $1,200 F Actual Meals Produced 3,000 Required a) Calculate actual labour hours used and actual labour rate per hour. Then calculate the overall labour variance. b) Explain what factors may have contributed to the cost and quantity variances and to overall efficiency