From a population of cans of coffee marked "12 ounces," a sample of 25 cans is selected and the contents of each can are weighed. The sample revealed a mean of 11.7 ounces and a sample standard deviation of 0.4 ounces. Test to see if the mean of the population is at least 12 ounces. (Assume the population is normally distributed.) Use a .05 level of significance.

In particular:

1. What are the null and alternative hypotheses?
2. What distribution will we use?
3. What is the critical value of your test statistic?
4. What is the calculated value?
5. What is your decision?