Let the mean of the population be 38 instances of from 6″ – 9″ hatchings per nest, and let the standard deviation of the mean be 3. What sample mean would have a confidence level of 95% or a 2.5% marg

Let the mean of the population be 38 instances of from 6″ – 9″ hatchings per nest, and let the standard deviation of the mean be 3. What sample mean would have a confidence level of 95% or a 2.5% margin of error?