21 students were selected for an informal study about a student study skills; 7 first-year, 7 second-year, and 7 third-year undergraduates were randomly selected. The students were given a study skills assessment having a maximum score of 100. We are interested in whether or not a difference exists somewhere between the three different year levels.

Year 1 Year 2 Year 3
82 71 74
93 62 73
61 85 87
74 94 91
69 78 56
70 66 78
53 71 87

Write the hypotheses for testing for a difference between the average score of three different year levels.