Level of significance in stats homework help?!!??

How can I figure this question out for my homework??

17. In a study of flavor enhancers in artificial lemonades, the following data, which list enhancers in milligrams/liter were obtained. At the level of significance of 0.05, test the claim that the three brands of artificial lemonade have the same mean amount of flavor enhancer. An answer without the calculations or TI window, the statistical justification and the appropriate hypotheses will be graded as incorrect.

Minute Maid
13.5
13.0
13.2
13.9
13.8
14.0
Crystal Light
12.7
12.5
12.6
12.7
13.0
13.0
Sam’s Choice
12.1
12.2
12.3
11.9
11.6
12.2