Cost estimates that are based as a guideline on real numbers, or figures derived after the completion of preliminary design work, are: a. Definitive estimates.
b. Feasibility estimates.
c. Parametric estimates.
d. Order of magnitude estimates

B. Feasibility estimates.

Explanation:

This is explained as an analysis used to determine the viability of an idea based on its risks and to check if it is legally and technically feasible.

Feasibility estimates are also used to determine whether a research study is likely to be delivered successfully, taking into account the practical aspects of managing the project. Moreso, feasibility assessments are not just about figures as it is also used to assess the relevance and intensity of the study for participants and the study

team. Large feasibility estimates will help identify possible problems with recruitment and may highlight

logistical challenges that may face sites involved with the study.

answer; by looking at total product,marginal product,and changes in both after changes in inputs

answerthe united states of america;