Hypothesis testing simulation: cola example

You recall the Cozy Cola company. Suppose we consider taking a small data set and finding a 95% confidence interval, rather than testing a specific null hypothesis. We will assume that the fill volumes of cans coming off the assembly line are normal with some mean, mu, and some standard deviation, sigma. Here are the data and 3 exercises.

The data

A random sample of 6 cans reveals volumes (ml) of:

 
350.7  356.6  353.5  355.2  349.7  350.5

Question: Why is the divisor n-1?

Exercise 2
Assume we know (from a vast, past history of the production process) that sigma = 2 ml. Find a 95% confidence interval for mu. (See Example 5.3.1, page 364.) What is the interpretation of this confidence interval? (Can you use it in a sentence?)

Exercise 3
Assume we do not know sigma. Find a 95% confidence interval for mu.