Labor cost, overtime and idle time

Louie Anderson works in the production department of Southwest Plasticworks as a machine operator. Louie, a long-time employee of Southwest, is paid on an hourly basis at a rate of $20 per hour. Louie works five 8-hour shifts per week Monday–Friday (40 hours). Any time Louie works over and above these 40 hours is considered overtime for which he is paid at a rate of time and a half ($30 per hour). If the overtime falls on weekends, Louie is paid at a rate of double time ($40 per hour). Louie is also paid an additional $20 per hour for any holidays worked, even if it is part of his regular 40 hours. Louie is paid his regular wages even if the machines are down (not operating) due to regular machine maintenance, slow order periods, or unexpected mechanical problems. These hours are considered "idle time."
During December Louie worked the following hours:
Hours worked including machine downtime
Machine downtime
Week 1 48 6.4
Week 2 44 2.0
Week 3 43 5.8
Week 4 46 3.5

Included in the total hours worked are two company holidays (Christmas Eve and Christmas Day) during Week 4. All overtime worked by Louie was Monday–Friday, except for the hours worked in Week 3; all of the Week 3 overtime hours were worked on a Saturday.

Required:
1. Calculate (a) direct manufacturing labor, (b) idle time, (c) overtime and holiday premium, and (d) total earnings for Louie in December.
2. Is idle time and overtime premium a direct or indirect cost of the products that Louie worked on in December? Explain.

1.(a) Total cost of hours worked at regular rates
48 hours × $20 per hour $ 960
44 hours × $20 per hour 880
43 hours × $20 per hour 860
46 hours × $20 per hour 920
3,620
Minus idle time
(6.4 hours × $20 per hour)
(2.0 hours × $20 per hour)
(5.8 hours × $20 per hour)
(3.5 hours × $20 per hour) 128
40
116
70
Total idle time 354
Direct manufacturing labor costs $3,266

(b) Idle time = 17.7 hours × $20 per hour =
(c) Overtime and holiday premium. $ 354
Week 1: Overtime (48 – 40) hours × Premium, $10 per hour $ 80
Week 2: Overtime (44 – 40) hours × Premium, $10 per hour 40
Week 3: Overtime (43 – 40) hours × Premium, $20 per hour 60
Week 4: Overtime (46 – 40) hours × Premium, $10 per hour 60
Week 4: Holiday 8 hours × 2 days × Premium, $20 per hour 320
Total overtime and holiday premium $ 560

(d) Total earnings in December
Direct manufacturing labor costs $3,266
Idle time 354
Overtime and holiday premium 560
Total earnings $4,180

2. Idle time caused by regular machine maintenance, slow order periods, or unexpected mechanical problems is an indirect cost of the product because it is not related to a specific product.
Overtime premium caused by the heavy overall volume of work is also an indirect cost because it is not related to a particular job that happened to be worked on during the overtime hours. If, however, the overtime is the result of a demanding "rush job," the overtime premium is a direct cost of that job.