You want to obtain a sample to estima population mean. Based on previous evidence, you believe the population standard deviation is approximately = 29.4. You would like to be 90% confident that your estimate is within 3 of the true population mean. How large of a sample size is required? n Do not round mid-calculation. However, you are encouraged to use a critical value accurate to three decimal places - this is important for the system to be able to give hints for incorrect answers.