Data Interpretation can be called as comprehension of mathematics. In reading comprehension, we have to study the passage and answer the questions followed by that.
Similarly, in Data Interpretation, data is given in the form of graphs, charts and tables followed by questions. We have to study, understand and analyse the data to solve the questions.
DATA: Data is a collection of facts, such as values or measurements. It can be numbers, words, measurements, observations or even just descriptions of things.
Information refers to data being arranged and presented in a systematic or an organise form, so that some useful inference can be drawn from the same. By data we generally mean quantities, figures, statistics, relating to any event.
What is DATA INTERPRETATION?
Data Interpretation is the extraction of maximum information from a given set of data or information. The data can be presented either in the form of a table or a bar chart or a pie chart or a line graph or as a combination of one of these formats.
Tips in solving DI questions: The following tips may help in answering problem solving questions that involve data analysis:
* Before starting DI section one should be very comfortable with numbers, calculations, fractions, percentages, averages, ratios. It helps in reducing the time required for solving the questions.
* Scan the data briefly to see what it is about, but do not attempt to analyse it in too much detail before reading a question. Focus on only those aspects of the data that are necessary to answer the question.
* Be sure to read all notes related to the data.
* When possible, try to make visual comparisons of the data given in a graph and estimate products and quotients rather than perform involved computations. Remember that these questions are to be answered only on the basis of the data given, everyday facts (such as the number of days in a year), and your knowledge of mathematics.
* Do not make use of specific information you recall that might relate to the particular situation on which the questions are based unless that information can be derived from the date provided.
Let us see some of the graphs of various types.
BAR DIAGRAM: A bar diagram is that two dimensional graphic representation where the elementary graphic objects are a set of rectangles (bars) drawn in parallel so that the extension of the same is proportional to the magnitude they intend to represent.
The rectangles, or bars, can be either horizontally or vertically positioned.
Simple bar diagram: If only one bar is given in the graph that is called simple bar diagram. E.g.: Following bar diagram gives the production of a company in various years.
Pb: What is the average production of the company over the years?
1) 350 2) 200 3) 450 4) 300 5) None of these
Sol: Average production
Multiple Bar diagram: When more than one adjacent vertical bars given then that is called multiple bar diagram.
E.g.: The bar-diagram gives imports and exports of a country over the years.
Pb: The imports in 2000-01 is what percent of the imports in 2002-03?
1) 25% 2) 100% 3) 20% 4) 80% 5) None of these
Sol: Imports in 2000 - 01 is 400
Imports in 2002 - 03 is 500
Sub-divided or component bar diagram: Sub-divided or component bar chart is used to represent data in which the total magnitude (bar) is divided into different parts or components. In this diagram, first we make simple bars for each class taking total magnitude in that class and then divide these simple bars into parts in the ratio of various components.
E.g.: Following graph gives the production of vehicles by three companies P, Q and R over the years. Production is in thousands.
Pb: What is the difference between the production of Q in 1997 and 1999?
1) 1250 2) 2000 3) 2500 4) 2250 5) None of these
Sol: Production of Q in 1997 is (40 -17.5) = 22.5 thousand
Production of Q in 1999 is (32.5-12.5) = 20 thousand
Difference = 22500 - 20000 = 2500 Hence answer is (3)
Line Graphs: A line graph is a type of graph, which displays information as a series of data points connected by straight line segments or A graph that uses points connected by lines to show how something changes in value.
E.g.1: The line graph gives the production of a company over the years.
Pb: In how many of the following years was the production of the company above the average?
1) 2 2) 4 3)1 4) 5 5) None of these
Sol: Average production
∴ Production is above average in three years. hence answer is (5)
E.g.2: Following graph shows the profit (in lakhs) of two companies A and B over the years.
Pb: What is the difference between the average profit of the companies A and B over the years?
1) 2.5 lakh 2) 5 lakh 3) 4.75 lakh 4) 3.33 lakh 5) None of these
Sol: Average profit of
PIE CHART: A pie chart is a circular chart divided into sectors. In a pie chart, the arc length of each sector (and consequently its central angle and area), is proportional to the quantity it represents.
E.g.: Following Pie-chart shows the different colours of cars using by 7200 persons in a town.
Pb: How many persons are using red colour cars?
1) 720 2) 1440 3) 1050 4) 360 5) None of these
Sol: Number of persons using red colour cars is
Hence answer (2)
Data is given in rows and columns. A row is a series of cells going horizontally across the table. A column is a series of cells going vertically or up and down the table.
E.g.: Following table gives the number of computers produced by five companies, P, Q, R, S and T over the years. Production is in thousands.
Pb: The percentage lead in the production of computers by company R from 2005 to 2006 was
1) 20% 2) 30% 3) 25% 4) 50% 5) 32.5%
Hence answer (4)