A company manufactures and sells a single product. The company operates a standard marginal costing system that enables the reporting of planning and operational variances. The original standard contribution per unit of the product for October, which was used to establish the budgeted contribution for the month, was as follow. R Selling Price 60 Direct Material 1.5kg @ R10/kg 15 Direct Labour 2hrs @ R15/hr 30 Contribution 15 Other information for October: . Sales and production quantities o Budgeted sales and production 40000units o Actual sales and production 42000units . A change in product specification was implements at the start of October, which required 20% additional material for each unit. The standard cost shown above was not revised to reflect the change Actual direct material purchased and used was 78000kg at R9.90/kg. The labour rate shown in the standard cost above was overestimated. The correct standard labour rate for the grade of labour required was R14.60 per hour. The actual rate paid was R15.20 per hour and the actual hours worked were 86000hours. The actual selling price per unit was R62. There were no opening inventory of raw materials or finished goods. Tip: First calculate the std contribution per unit for October Required: 4.1 Calculate the following variances: Sales price variance Material price variance Material usage variance Labour rate variance Labour efficiency variance 4.2 Calculate the total actual contribution