posted by Sarah .
Use the given information to find the minimum sample size required to estimate an unknown population mean μ.
How many commuters must be randomly selected to estimate the mean driving time of Chicago commuters? We want 99% confidence that the sample mean is within 4 minutes of the population mean, and the population standard deviation is known to be 6 minutes.
I have no idea how to go about solving the above question. Please help if you can.