A simple random sample of 60 items resulted in a sample mean of 71. The population standard deviation is 15.
a. Compute the 95% confidence interval for the population mean (to 1 decimal).
( , )
b. Assume that the same sample mean was obtained from a sample of 120 items. Provide a 95% confidence interval for the population mean (to 2 decimals).
( , )
c. What is the effect of a larger sample size on the margin of error?
Select
It increases
It decreases
It stays the same
It cannot be determined from the given data
Item 5
