Answer:
1. $4,000,000
2. $4,480,000
3. Jack's continue to process them further into lumber.
Step-by-step explanation:
1. Total contribution to income from selling the logs for log cabin construction:
= No. of large trees receives each period × Selling price per-unit
= 8,000 × $500
= $4,000,000
2. Total contribution to income from processing the logs into lumber:
= 8,000 × 800 × ($0.75 - $0.05)
= 8,000 × 800 × 0.70
= $4,480,000
3. Jack's continue to process them further into lumber only, because income from processing it as lumber is greater than log.