You have decided to use unstratified mean-per-unit sampling.

Required:

Indicate the effect on sample size (increase, decrease, no effect, or indeterminate)

for each of the following changes, and explain your answer.

a. Increase in the population size.

b. Increase in the standard deviation.

c. Increase in the desired precision from \($200,000\) to \($300,000.\)

d. Rather than test the population without stratification, you decide to stratify it into three strata: all of the items over \($100,000\) in one stratum, all of the items between

\($25,000\) and \($100,000\) in a second stratum, and the items less than \($25,000\) in a third stratum.