Answer :
Final answer:
The accuracy of top-down estimates is commonly within the range of minus 10% to plus 30%, reflecting the approximate nature of these estimates and their reliance on historical data and uncertain factors.
Explanation:
The accuracy of top-down estimates will often vary depending on the complexity and nature of the project being estimated. These estimates are broad, usually based on previous experience or statistical methods, and not as reliable as detailed bottom-up estimates. In general, a common range for the potential error in top-down estimates is minus 10% to plus 30%. This suggests that the estimates could be 10% less or 30% more than the actual results. The reason for this range is that top-down estimates are often based on approximate assessments and historical data, and as such, they carry a degree of uncertainty. It is important to remember that when making top-down estimates, precision should not exceed the one's place to avoid a false sense of accuracy, as top-down estimates cannot typically guarantee precision below ±5% of the total estimate.
