Need help find part B of the question.

A simple random sample of 60 items resulted in a sample mean of 92. The population standard deviation is 18. a. Compute the 95% confidence interval for the population mean (to 1 decimal). ( 87.5 96.5 1 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? It decreases