Use 6.81 days as a planning value for the population standard deviation a. Assuming 95% confidence, what sample size would be required to obtain a margin of error of 1 days? Do not round intermediate calculations. Round your answer up to the nearest whole number. b. If the precision statement was made with 90% confidence, what sample size would be required to obtain a margin of error of 3 days? Do not round intermediate calculations. Round your answer up to the nearest whole number