Question

For the 40 students in a class, the results of their second English test are plotted against the results of their first English test. It was found that for each student, the result of the second test is better than that of the first test (i.e., the second test score is higher). Which of the following must be true about the relationship between the students’ second test results and their first test results?
I. If student A scores better than student B in the first test, then student A also scores better than student B in the second test.
II. The correlation between the students’ second test results and first test results is positive.

A) Neither (I) nor (II).

B) (I) and (II).

C) (II) only

D) (I) only

Answer 1

We have given that the results of their second English test are plotted against the results of their first English test & it was found that the result of second test is better than that of first test. That is if the first test score increase, there will be increase the second test score. So, there will be positive correlation between first test score & second test score.

But, we can not say that there will if student A score better than student B, then student A also scores better than student B in the second test. Because, it is not possible in all situations if A scores better than B in 1st then A also scores better than B in 2nd test. It may happen that if A scores better than B in first test then B can scores betteer than in second test. So, we can't be 100% sure about this.

So, option C is correct. i.e. statement ii) is true but not i).