A test was conducted on two different classes to see if there was any significant difference between the performances of two teachers. The final exam scores of 15 students were sampled in the first-class yields a mean score of 82 with a standard deviation of 2.4. The mean final exam score of the second class was 84 with a standard deviation of 1.7 using a sample of 12 students. Determine if there is any major difference at a 5% significance level.