R.N Institute of Professional Studies D-12 Main Kanti Nagar Krishna - PDF document

R.N Institute of Professional Studies D-12 Main Kanti Nagar Krishna Nagar Delhi-51 CHAPTER-6 DIAGRAMMATIC PRESENTATION OF DATA Bar Diagrams and Pie Diagrams MEANING:- Diagrams provide a way of presenting the data visually so as to bring out the salient features of the data. They create a lasting impression on the mind of an observer of the numerical values which can be easily remembered. Diagrams give bird ’ s-eye view to the whole mass of data that have been collected about any problem. Diagrammatic representation of data is a method of visual acts and in appearing to the eye and the mind. UTILITY OF DIAGRAMMATIC PRESENTATION 1. With the help of diagrams, the most complex data become simple and understandable. 2. Diagrams are attractive and have great memorizing effect. The impressions created by diagrams last much longer than those presented of data. 3. Diagrammatic presentation of data saves much time and labour in comparison to other techniques of presentation of data. 4. diagrams create a long lasting impression on the mind of an observer of the relative magnitude of the numerical values which can be easily remembered. 5. diagrams are becoming popular in various fields. RULES NFOR DRAWING DIAGRAMS 1. Heading:- There should be a proper heading for every drawing diagram. The heading should be simple, clear, precise and self-explanatory. 2. Size:- The size of diagrams should be according to the space available. The size of the diagram should be neither too large nor too small. It should be attractive. 3. Scale. Diagram should be drawn to proper and accurate scale. 4. Accuracy:- It is also an art to draw diagrams. While preparing diagrams the accuracy should be kept in mind. If diagrams are in accurate form, they will provide us exact result. 5. Simplicity:- Diagrams drawn should not be complex ones. They should be simple as far as possible so that even the layman can understand them clearly and quickly. 6. Use of colours and signs. Different types of lines, or shades, colours, etc. should be used so that the reader can easily understand the diagram. 7. Clarity:- Clarity/Neatness should be strictly observed and he diagram be drawn with the help of geometric instruments. 8. Index:- In order to clarity certain points about the diagram, index/footnote may be given at the bottom of the diagram. KIND OF DIAGRAMS 1. Line Diagrams 2. Simple Bar Diagrams 3. Multiple Bar Diagrams 4. Sub-Divided Bar Diagrams 5. Duo-Directional Or Bilateral Bar Diagrams 6. Circular Or Pie Diagrams

1.Line diagrams:- When the number of items is large lines may be drawn vertically. These lines have no width and are not so attractive. 2. Simple Bar diagrams:- In simple bar diagrams one bar represents only one figure and as such there will be as many bars as the number of figures. Bars in these diagrams are of he same breadth. Such diagrams represent only one particular type of data. 3. Multiple Bar Diagram. These diagrams represent more than one type of data at a time. Thus if each year two bars are constructed- one representing the amount of exports and the other representing the amount of imports, the diagrams would be multiple-bar diagram. Generally bars are differentiated by colours to show the behaviour of two sets of series. 4. Sub- Divided Bar Diagrams. These are those diagrams which present, simultaneously, total values and parts there in a set of a data. To indicate different parts of the bars, these are shaded with colours. Different parts of a bar must be shown in the same order for all the bars of a diagrams. 5. Duo-Directional or bilateral Diagrams:- These diagrams are drawn to represent two different attributes. The bars can have both positive and negative values. Positive values are shown above the base line and negative values below it. 6. Circular or Pie Diagrams. Similar to sub-divided rectangles, used to re-represent the total magnitude and its various components, a circle may be divides into various sectors representing the respective components. Such a diagram is known as sector diagram. The circle comprises 360 o. Accordingly, percentage of a variable are fixed as multiples of 360 o . Different parts of a circle may be shaded with different colours highlighting, different values. LIMITATIONS OF DIAGRAMMATIC REPRESENTATION 1. Diagrams are constructed on the basis of approximation. Exact measurement is not possible here. 2. Diagrams do not provide detailed information. They only show a limited amount of information. 3. If the difference between the data is very less then it can not be explained with the help of diagram. 4. Two-or – three-dimensional diagrams are difficult to understand than the facts contained in a statistical table. 5. Diagrams are liable to be easily misinterpreted. They may often have misleading impression to people. 6. Diagrams can not show too many facts as a statistical table can do. 7. It is time and labour consuming to construct diagrams. Short Questions 1.Distinguish between a bar diagram & a histogram. Ans. Bar diagram is different from a histogram in two ways: (a)In a bar diagram, we are concerned with the length of the bar. They are one-dimensional form of presentation. But , a histogram is a two-dimensional form of presentation where length & width both are taken into account. (b)In a bar diagram, there is gap between different bars whereas in a histogram, there is no gap in between the different rectangles.

2.What do you mean by pie diagram? Write the steps involved in constructing it. Ans . A pie diagram is a circle diagram whose area is proportionally divided among the components it represents. The following steps are involved in constructing it. (a)Construct a circle of an appropriate size with a compass. (b)Pie diagrams are usually not drawn with absolute values of a category. The values of each category are first expressed as % of the total value of all the categories. (360° (c)Each % figure of every component is multiplied by 3.6 to find out its respective angle. ( 100 = 3.6°) (d)Represent various components by different shades, designs or colours for proper identification. Numericals 1.Make a percentage sub-divided bar diagram Year Arts Commerce Science 1990 100 300 600 1991 150 450 600 1992 130 550 820 2.Represent the following data with the help of multiple bar diagram. Year 2003 2004 2005 2006 Exports (crore in 73 80 85 80 Rs) Imports (crore in 70 72 75 85 Rs) 3.Draw the pie diagram to represent the following information of expenditure by a family: Items of Food Education Housing Clothing Miscellaneous Expenditure % age of total 60 15 10 10 5 expenditure 4. Make a percentage sub-divided bar diagram Year Arts Commerce Science 1990 100 300 600 1991 150 450 600 1992 130 550 820 5. Represent the following data with the help of multiple bar diagram. Year 2003 2004 2005 2006 Exports (crore in Rs) 73 80 85 80 Imports(crore in Rs) 70 72 75 85

6. Draw pie diagram to represent the following information of expenditure by a family: Items of Expenditure Food Education Housing Clothing Miscellaneous % age of total expenditure 60 15 10 10 5 7 .Use pie diagram to represent the following data. Expenditure item Amount(Rs) Salary and Wages 45,000 Rent 15,000 Interest Payment 8,000 Repair 20,000 Capital Formation 12,000 8.Make a suitable diagram of the following data on population in India: Year 1951 1961 1971 1981 1991 2001 2011 Population (crore) 36.1 43.9 54.8 68.3 84.6 102.8 121.0 9.The result of X class students is given as follow: Years Ist Division IInd Division IIIrd Division 2015 10 30 50 2016 12 45 70 2017 14 50 60 2018 11 40 75 Draw a multiple bar diagram. 10. Make a bar diagram of the following data on India ’ s population: Year 1971 1981 1991 2001 2011 Population (crore) 54.8 68.3 84.6 102.8 121.0 11. Make a multiple bar diagram of the following data: Faculty Number of Students 2014-15 2015-16 2016-17 Arts 600 550 500 Science 400 500 600 Commerce 200 250 300 12.Present the data given by means of a percentage bar diagram: Gender Enrolled (%) Out of school (%) Boys 91.5 8.5 Girls 58.6 41.4 All 78.0 22.0

13. Following table shows estimates of cost of production of certain commodities. Present the data in the form of a sub-divided bar diagram: Estimate of cost Goods A B C D Raw material 50 40 45 50 Wages 40 40 40 40 Fixed costs 10 12 15 15 Office expenses 10 8 10 5 Total Cost 110 100 110 110 14. What do you mean by a circular diagram? Present the data on the expenditure of a labour- family in the form of a circular diagram: Items of Expenditure Food Clothing Housing Fuel and Light Others Percentage of Income Spent 5 15 12 5 3