Scatter diagram studies correlation between two variables

Scatter diagram studies correlation between two variables but it does not measure the precise
extent of correlation. In the context of above statement explain the merits and demerits of scatter diagram.

The main merits and demerits of scatter diagram are
Merits of Scatter Diagram .
(i) It is simple and a non-mathematical method of studying correlation between two variables.
(ii) It can be easily understood and interpreted.
(iii) It is not influenced by the size of extreme values.
Demerits of Scatter Diagram
(i) It is only a qualitative expression rather than a quantitative expression.
(ii) It gives only a broad and rough idea of the degree and nature of correlation between two variables.
(iii) This method does not indicate the exact numerical value of correlation.