You want to obtain a sample to estimate a population mean. Based on previous evidence, you believe the population standard deviation is approximately σ=55.5σ=55.5. You would like to be 99% confident...

You want to obtain a sample to estimate a population mean. Based on previous evidence, you believe the population standard deviation is approximately σ=55.5σ=55.5. You would like to be 99% confident that your estimate is within 5 of the true population mean. How large of a sample size is required?