The management of a major dairy wanted to determine the average ounces of milk consumed per resident in the state of Montana. Past trends indicated that the variation in milk consumption was four ounces. A 95 percent confidence level is required, and the error is not to exceed +/- .5 ounces.
a. What sample size would you recommend? Show your calculations.
b. Management wanted to double the level of precision and increase the level of confidence to 99 percent. What sample size would you recommend? Show your calculations. Comment on your results.