Coca-Cola's standard cost per 1,000 liters of syrup includes 500 hours of direct labor at $25 per hour and $3,000 of direct materials. During May, 50,000 liters of syrup were produced using 25,200 hours of direct labor at a total cost of $648,000 and $150,000 of direct materials.

Requirements:

1. Calculate the direct labor rate variance.
2. Calculate the direct labor efficiency variance.
3. Determine the direct materials price variance.
4. Determine the direct materials quantity variance.