A biologist wishes to estimate the effect of an antibiotic on the growth of a partic...

A biologist wishes to estimate the effect of an antibiotic on the growth of a particular bacteriumby examining the mean amount of bacteria present per plate of culture when a fixed amountof the antibiotic is applied. Previous experimentation with the antibiotic on this type of bacteria indicates that the standard deviation of the amount of bacteria present is approximately . Use this information to determine the number of observations (cultures that must be developed and then tested) to estimate the mean amount of bacteria present, using a 99% confidence interval with a half-width of ^.