Question

A simple random sample of 60 items resulted in a sample mean of 80. The population standard deviation is 15 .

a. Compute the 95% confidence interval for the population mean. Round your answers to one decimal place.
( ,  )

b. Assume that the same sample mean was obtained from a sample of 120 items. Provide a 95% confidence interval for the population mean. Round your answers to two decimal places.
( ,  )

c. What is the effect of a larger sample size on the interval estimate?

Larger sample provides a  - Select your answer - larger smaller Item 5  margin of error.