You are a small construction firm and do not have access to equipment able to move boulders in excess of 15' in diameter. For each boulder you encounter greater than 15' in diameter, you have to outsource some work. If you encounter a boulder in excess if 15' in diameter, you plan to hire a demolition expert to blast the boulder to manageable pieces. The combined blasting/removal time for a boulder in excess of 15' is a half-day, and will cost $10,000 per boulder.

You hired a local geologist to complete a study of the construction site and focus on the section of earth requiring movement. The geologist states that there is a 10% chance that all boulders will be less than 15' in diameter, a 55% chance that you will encounter 4 boulders in excess of 15' in diameter, and a 35% chance that you will encounter 8 boulders in excess of 15' in diameter.

1. Construct a decision tree depicting both expected cost and expected duration of the ADDITIONAL time/funds required for moving the earth given three alternatives of encountering 0, 4, and 8 boulders in excess of 15' and using the demolition expert.

You'vejust learned that you also have the option of hiring a larger construction firm, with larger equipment, to remove boulders in excess of 15'. This company is able to completely remove one boulder in excess of 15', but it requires an entire day. They charge $8,000 per boulder.

2. Construct the associated decision tree depicting the expected cost and expected duration of the ADDITIONAL time/funds required for moving the earth given three alternatives of encountering 0, 4, and 8 boulders in excess of 15' and using the larger company.