A simple random sample of 90 items from a population with = 7 resulted in a sample mean of 38. If required, round your

A simple random sample of 90 items from a population with σ = 7 resulted in a sample mean of 38.

If required, round your answers to two decimal places.

a. Provide a 90% confidence interval for the population mean.
_____ to _____

b. Provide a 95% confidence interval for the population mean.
_____ to _____

c. Provide a 99% confidence interval for the population mean.
_____ to _____