A coffee machine dispenses coffee into paper cups. Youre supposed to get 10 ounces of coffee, but the amount varies slightly from cup to cup. Here are the amounts measured in a random sample of 20 cups. Is there evidence that the machine is shortchanging customers? (You may assume that the number of ounces dispensed in normally distributed)

9.9 9.7 10.0 10.1 9.9 9.6 9.8 9.8 10.0 9.5

10.1 9.9 9.6 10.2 9.8 10.0 9.9 9.5 9.9 9.7

Find a 95% confidence interval for the number of ounces dispensed by the machine.

Write a sentence giving your results in the context of the problem.

What does 95% confidence mean in this problem?

Does your confidence interval suggest that the company is or is not short-changing their customers? Explain.