Top-down estimates (You may select more than one answer. Single click the box with the question mark to produce a check mark for a correct answer and double click the box with the question mark to empty the box for a wrong answer. Any boxes left with a question mark will be automatically graded as incorrect.)

• are used in the project conceptual phase
• depend on surrogate measures such as weight or square feet or ratios
• do not consider individual activity issues and problems
• are good for rough estimates
• can help select and prioritize projects
• are made by people familiar with the task
• help to gain buy-in on the validity of the estimate
• improve the accuracy of the estimate
• should be preferred if estimating cost is reasonable

Bottom up estimates (You may select more than one answer. Single click the box with the question mark to produce a check mark for a correct answer and double click the box with the question mark to empty the box for a wrong answer. Any boxes left with a question mark will be automatically graded as incorrect.)

• are made by people familiar with the task
• help to gain buy-in on the validity of the estimate
• improve the accuracy of the estimate
• should be preferred if estimating cost is reasonable
• are used in the project conceptual phase
• depend on surrogate measures such as weight or square feet or ratios
• do not consider individual activity issues and problems
• are good for rough estimates
• can help select and prioritize projects

Why is it difficult to estimate the costs and benefits of mega projects (e.g. airports, stadiums)? (You may select more than one answer. Single click the box with the question mark to produce a check mark for a correct answer and double click the box with the question mark to empty the box for a wrong answer. Any boxes left with a question mark will be automatically graded as incorrect.)

• Small scope but large complexity is a double whammy
• It is difficult to estimate costs far into the future
• Deception may be used in promoting projects
• The public good will outweigh the costs
• Promoters may be too optimistic or uninformed

there is more than one answers and please let me know which one is check and uncheck thank you!