Answer with explanation:
From a normally distributed population, if two samples of size less than 30 taken out , then we use t-test to test the difference between the population means.
The conditions which are necessary to use a t-test are :-
1. Each population must have normal distribution.
2. Both the samples must be independent.
Now, if a teacher is experimenting with a new computer-based instruction and conducts a study to test its effectiveness, then to use a t-test all the above conditions are necessary.