When is it most appropriate to use the threepoint method whe

When is it most appropriate to use the three-point method? when sampling a stream according to USGS regulations?

Solution

three-point method is used in management systems and applications for the construction of an approximate probability distribution representing the outcome of future events, where very limited information is known. While the distribution used for the approximation might be a normal distribution, this is not always so and, for example a triangular distribution might be used.

It is used in PERT. which is even oriented network and we work on probabilistic mdel.

In three-point estimation, three figures are produced initially for every distribution that is required, based on prior experience or best-guesses:

These are combined to yield either a full probability distribution.

The accuracy attributed to the results derived can be no better than the accuracy inherent in the 3 initial points

These are used in non repititive type of projects.

b.

The U.S. Geological Survey (USGS), provides the information needed for accurate assessment, protection, and wise management of the Nation’s water resources. It collects, and assists others in collecting, the data needed to determine the quality and quantity of our surface and subsurface water bodies.

Its aim is to maintain maintain and protect our human and environmental health, and are designed to address such questions as:

• Is our water of acceptable quality for drinking or swimming, for irrigation or aquatic habitat?

• Is water quality getting better or worse?

What is causing the pollution or deterioration of a given lake, stream, or aquifer?