Please answer the following question as is. No additional information is needed. Thank you.

The management of a major non-alcoholic beverage manufacturer wants to determine the average amount of soda (in ounces) consumed per resident in the state of New Jersey per day. Past trends indicate that the variation in soda consumption was 4 ounces. A 95% confidence level is required and the error is not to exceed +/- ounce.

a. What sample size do you recommend? Show your calculations.

b. Management wants to double the level of precision and increase the confidence level to 99%. What sample size would you recommend now? Show the calculations.