What do they mean? with confidence interval? I'm just starting out and this is part of our homework for class. I don't understand it.
A simple random sample of 10 items resulted in a sample mean of 70. The population standard deviation is = 15.
a. Compute the 95% confidence interval for the population mean. Round your answers to three decimal places. Write your answer using parentheses and a comma, in the form (n1,n2).
b. Assume that the same sample mean was obtained from a sample of 130 items. Provide a 95% confidence interval for the population mean. Round your answers to five decimal places.