Graphing of Data The second method for summarizing data is by using graphing. Graphs may be such: Bar graph, Pie charts, Histograms, Polygon, Ogive and Box plot, graphing data gives the user a nice overview of the essential features of the data. Each graph should have: A descriptive Title. Labeled axis. An indication of the units of observation

Graphing of Data The type of chart to be used depend on the nature of data as: Qualitative data (Categorical data) and Quantative discrete data should be use: Bar charts (الرسم البياني). Pie charts.

Graphing of Data The type of chart to be used depend on the nature of data as: Quantative continuous data should be use: Histograms (المدرج التكراري). Polygon (المضلع التكراري). Ogive (القوسي). Box plot (رسم الصندوق).

Graphing of Data The type of chart to be used depend on the nature of data as: Quantative continuous data should be use: Histograms (المدرج التكراري). Polygon (المضلع التكراري). Ogive (القوسي). Box plot (رسم الصندوق).

Graphing of Data Bar chart It used with categorical or numerical discrete data. The frequency or relative frequency of a categorical variable can be shown easily in a bar chart. Each bar represent on category and its height is the frequency or the relative frequency. Bars should be separated. It is very important that Y-axis start with 0.

Graphing of Data Fruit People Apple 35 Orange 30 Banana 10 Kiwifruit Example: The data in table bellow represent the fruits and frequency of 145 people where love these fruits. Fruit People Apple 35 Orange 30 Banana 10 Kiwifruit 25 Blueberry 40 Grapes 5

Graphing of Data Then we can represent the above table in Bar chart as:

Graphing of Data Y-axes height is people frequency. Where: Y-axes height is people frequency. X-axes represent the fruit types. A Nicey fruit is the descriptive Title. Fruits and Number of people are the labeled axis. Right box is the indication of units.

Graphing of Data Accompanying bar chart If we have a nominal categorical variable such [(Male, Female), (Survived, Died)] we can present data with a grouped bar chart to allow an easy comparisons between groups.

Graphing of Data Example: We have a Titanic Mortality data and it was summarized in a companying table as (Morio Traiola, Elementary statistics (2004), pp. 155):   Men Women Boys Girls Total Survived 332 318 29 27 706 Died 1360 104 35 18 1517 1692 422 64 45 2223

Graphing of Data Then we represent the data on table in a companying Bar chart as:

Graphing of Data Pie Chart Pie chart is an alternative graph to present one categorical variable in the form of graph. Each slice of pie correspond to frequency or relative frequency of categorical variable. If we want to make comparisons between variables, we need to build more than one pie chart.

Graphing of Data Pie Chart The angle of any slice is obtained by the following formula: Or

Graphing of Data Example: The same example of fruits but with relative frequency calculations: Fruit People R.F Apple 35 24.13793 Orange 30 20.68966 Banana 10 6.896552 Kiwifruit 25 17.24138 Blueberry 40 27.58621 Grapes 5 3.448276 Total 145 100

Graphing of Data Before we start to graph the data we should calculate the slice angle for people frequency and for relative frequency as: Angle slice for:

Graphing of Data Angle slice for:

Graphing of Data Then we draw the Pie graph as:

Graphing of Data for relative Frequency (R.F): Angle slice for:

Graphing of Data for relative Frequency (R.F): Angle slice for:

Graphing of Data Then we draw the Pie graph as: