Define the t-test for the difference of two means. Write the formula for the t-statistic when the population variances are assumed equal. List the assumptions of the test.
2.Two groups of students were taught using different teaching methods. Their marks are given below:
Method A: 85, 89, 76, 82, 67, 90
Method B: 72, 78, 69, 65, 81, 74, 77
At the 5% level of significance, test whether there is a significant difference between the mean marks of the two groups.