A study was conducted to investigate some effects of physical training. Sample data are given below with all weights given in kilograms.

Pre training: 98 57 62 69 74 77 59 92 70 85

Post training: 94 57 62 69 66 76 55 89 70 84

At 1% significance level test whether the mean of the Post training weight is less than that of pre-training weight. What type of error could you have made in your decision.