You want to obtain a sample to estimate a population mean

Last updated: 7/25/2022

You want to obtain a sample to estimate a population mean. Based on previous evidence, you believe the population standard deviation is approximately σ = 26.7. You would like to be 98% confident that your estimate is within 5 of the true population mean. How large of a sample size is required? 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.