a. Using difference estimation, calculate the preliminary sample size for a to e from the information provided. Apply the finite correction factor when it is appropriate.

b. In general, what is the effect on the preliminary sample size (increase, decrease, no effect, or cannot determine without additional information) of each of the following independent changes, assuming the other components of sample size are held constant ?

a b C d Population size Alpha risk 5,000 20% 10,000 5,000 10,000 5,000 49% 20% 25% 5% Beta risk 5% 5% 1% 10% 5% Allowable error 50,000 80,000 50,000 80,000 50,000 Estimated standard 100 150 100 150 100 deviation Estimated point estimate 20,000 30,000 20,000 30,000 20,000