Which tool and technique uses a statical relationship between historical data and other variables to calculate estimates?

A.
Analogous estimating

B.
Three-poit estimates

C.
Parametric estimating

D.
Bottom-up estimating

Explanation:
Parametric Estimating: Refers, primarily, to an estimation technique which utilizes the statistical relationship that exists between a series of historical data and a particular delineated list of other variables. Some examples of these variables include square footage in a contraction project, the number of lines or code that exist in a software application, and other similar variables. This information is them implemented for the purposes of calculating and demonstrating an estimate for the entity of activity parameters. One valuable aspect of parametric estimating is the higher levels of accuracy that can be built into it depending on how sophisticated the original data that was built into the estimate turns out to have been.

Analogous Estimating It is also known as “Top Down” Estimation.
It uses estimations from previous activities to estimate future durations. The validity of duration estimates derived using this method depends on:
– historical information
– similarity of the historical projects
– expert judgement

Three Point Estimation: is a technique used to estimate the time required for a project based on historical information. This includes:
Most Optimistic:Best case scenario in which nothing goes wrong and all conditions are optimal.
Most Likely:The most likely duration and there may be some problem but a lot will go right.
Most Pessimistic: The worst case scenario which everything goes wrong.

Bottom-Up Cost Estimation Is
*An estimating the cost for each work package in the WBS.
*The most accurate method but it is also the most challenging, costly and time consuming.