A police investigator is interested in estimating the mean blood alcohol content (BAC) of people arrested for driving under the influence. Her sample study includes 225 individuals with a mean BAC of 0.130 g/dL, with a standard deviation of 0.062 g/dL. a. Calculate the 90% margin of error, rounded to 4 decimal places. (2 marks) b. What is the 95% confidence interval for the mean BAC, rounded to 3 decimal places? (2 marks)