Question

6. In one class, the correlation between scores on the final and the midterm was 0.50, while the correlation between the scores on the final and the homework was 0.25. True or false, and explain the relationship between the final scores and the midterm scores is twice as linear as the relationship between the final scores and the homework scores. 7. The figure below has six scatter diagrams for hypothetical data. The correla- tion coefficients, in scrambled order, are: -0.85 -0.38 -1.00 0.06 0.97 0.62 Match the scatter diagrams with the correlation coefficients.

Answer 1

6. The given statement is True. The correlation measures the strength of linear relationship between two variables. Since, the correlation between the scores on final and midterm is twice the correlation between the scores on the final and homework, we can conclude the former linear relationship is twice as linear as later.

7. The first left graph represents moderate positive linear relationship. So, the possible correlation value would be 0.62.

The first right graph demonstrates perfect negative linear relationship. So, the possible correlation value would be -1.

The second left graph exhibits quite strong negative linear relationship. So, the possible correlation value would be - 0.85.

The second right graph represents very strong positive linear relationship. So, the possible correlation value would be 0.97.

The third left graph demonstrates very weak positive linear relationship. So, the possible correlation value would be 0.06.

The third right graph exhibits weak negative linear relationship. So, the possible correlation value would be -0.38.