Sedimentary deposits in reservoirs. Geologists have successfully used statistical models to evaluate the nature of sedimentary deposits (called facies) in reservoirs. One of the models’ key parameters is the proportion P of facies bodies in a reservoir. An article in Mathematical Geology

(Apr. 1995) demonstrated that the number of facies bodies that must be sampled to estimate P satisfactorily is approximately normally distributed with m = 99 and s = 4.3.

How many facies bodies are required to estimate P satisfactorily for 99% of the reservoirs evaluated?