Question

Have you ever purchased a large hot coffee from Dunkin Doughnuts? How about a large iced coffee? One thing I’ve noticed is that the cups are noticeably different sizes. This probably takes the amount of ice in an iced coffee. I want to know if the average weight in a large hot coffee is the same as the average weight in an iced coffee (with the ice removed). I weighed 5 large hot coffees and found the weight was 24, 22, 20, 23, and 21. I also weighed 5 large iced coffees and found the weight was 24, 20, 26, 29, and 32. Assume a random sample was drawn. I believe this to be a two tailed test.

Answer 1

Null Hypothesis H0: Average weight in a large hot coffee is equal to the average weight in an iced coffee.

Alternate Hypothesis H1: Average weight in a large hot coffee is not equal to the average weight in an iced coffee.

Since the alternate hypothesis tests for both sides - Average weight in a large hot coffee is less than the average weight in an iced coffee or Average weight in a large hot coffee is greater than the average weight in an iced coffee, this is a two-tailed test.