Bottom up estimates $($You may select more than one answer. Single click the box for a correct answer and double click the box with the question mark to empty t 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