The standard labour component and the actual labour component engaged during the month are given below:

Skilled Semi-skilled Unskilled

(a) Standard number of workers in a group 30 10 10

(b) Standard wage rate (E) 20 12 8

(c) Actual number of workers employed during the month in the group

24 15 12

(d) Actual wage rate per hour (E) 24 10 8

During the month of 200 working hours, the group produced 9,600 standard hours of work.

You are required to calculate:

1. Wage rate variance
2. Labour efficiency variance
3. Labour mix variance
4. Total labour cost variance