You want to obtain a sample to estimate a population mean. Based on previous evidence, you believe the population standard deviation is approximately = 41.6. You would like to be 99% confident that your estimate is within 2.5 of the true population mean. How large of a sample size is required? [Do not round mid-calculation. However, use a critical value rounded to three decimal places - this is important for the system to check answers correctly.] n =