The following Table gives the height and weight of 10 students in a class. Draw a scatter diagram and interprete whether the correlation is positive or negative.
|
Height (cms). |
180 |
150 |
158 |
165 |
175 |
163 |
145 |
195 |
180 |
155 |
|
Weight (kgs.) |
65 |
54 |
55 |
61 |
60 |
54 |
50 |
63 |
65 |
50 |
Scatter diagram : Let us denote the height as X and weight as Y to plot the two variables.
Fig. 2.8:
Interpretation : The two variables have a high degree of positive correlation since the dots cluster around the line that moves upwards from the left-hand corner to the right hand corner.
Advantages of Scatter Diagram : (i) It is a simple method which can be followed with ease.
(ii) It is not affected by the value of the extreme items.
Limitations of Scatter Diagram : Although it gives a bird’s eye view of the relationship between two variables, yet it gives no exact idea about the degree of correlation. Besides, it cannot be treated mathematically.
