The table below lists the weights of some colleage students in September and later in February of their freshman year. September weight 65 58 71 70 53 60 68 50 66 55 70 80 61 53 73 51 74 52 69 76 58 59 71 61 February weight 68 55 67 76 56 58 74 55 67 53 67 74 58 56 76 56 68 55 64 72 58 58 77 55 At the 0.05 significance level, test the claim of no difference between September weights and February weights.

test statistic:

critical value: