Graphical presentation

A graph is a vusual form of presentation.it enable us to present data in a simple.clear and effective manner.

1.Every graph must have a title.indicating the facts presented by the graph.

2.It is necessary to plot the independent variables on the horizontal axis and dependent variable on the vertical axis.

3.Problem arises regarding the choice of a suitable scale.The choice must accommodate the whole data.

4.The principle of drawing graph is that the vertical scale must start from ziro.If the fluctuation are quite small compared to the size of -variables,there is no need of showing the entire vertical scale from the orgin.The scale just sufficient for the purpose need be shown and for this purpose a false line may be used.The portion of the scale which lies between zero and the smallest variable is ommited,by drawing two horizontal lines.

5.The graph must not be overcrowded with curves.

6.If more than one variables is plotted on the same graph,it is necessary to distinguish themby different line viz....dottef lines,broken lines,dots,dot-cum-dash ,thick,thin dashed line etc

7.Index should be given to show the scale and the meaning of different curves.

8.All lettering must be horizontal.

9.It should be rememberd that for-every value ' of independent variable,there is a corresponding value of the dependent variable.It is these matched values (pair of value)that are to be plotted.Each pair of value is represented on the graph by a point.This point corresponds to the values on X=axis and Y-axix.

10.source of infromation should be mentioned as footnote.

Line graph

Only one variable is to be represented graphically,we use line graph.Line charts many also be used to show how the value of a variable changes over time.unlike bar and column charts .line charts imply  continuous change rather than a number of discrete improvement and decline.for this reason ,line charts are better at implying a trend.

Be carefu when interpreting such charts that you don't automatically assume intermediate values by the line placement.