Page 283 - Start Up Mathematics_7

16 Data Handling

In today’s world with easy access to data, there is hardly any branch of studies, be it Mathematics,
Economics, Science, Medicine, Psychology, etc. where statistical application does not play an
important role. Scientists, businessmen, researchers, economists, etc. with the help of various
statistical tools decide the future course of action and project estimates for future. Meteorologists
use statistics to forecast weather and predict heavy rains and storms.
In the previous class, you have learnt to collect and tabulate data and put it in the form of bar
graphs. Collection, organization and presentation of data is of great significance as it not only
helps in analysis and interpretation but important inferences can be drawn from it.

In this chapter, we are going to learn how to collect relevant data and present it as frequency
distribution. We will also learn to evaluate 3 representative values—mean, median and mode,
review bar graph and learn more about it.

Collection of Relevant Data

Before collecting the data, we should know for what purpose it is needed. In order to get useful
results, one should know clearly what type of problem is at hand and the exact data required for it.
Suppose we need to know the performance of India in the XIX Commonwealth Games. It can have
two interpretations. One is the performance of our country vis-a-vis other countries. For this, we
must have the medal tallies of all the countries in the XIX Commonwealth Games. If the aim is
to study the relative performance of India over the years in the Commonwealth Games, then we
need to study the data regarding the number of medals (Gold, Silver and Bronze) won by India in
the XIX Commonwealth Games vis-a-vis its own performance in the past. Thus, one can observe
the difference in the data required for the two situations.

Discuss with your friends, what type of data is required in the following situations:
• Performance of your class in Mathematics test.
• Children whose parents are in services are more serious in studies.
• Number of members in different families of your neighbourhood.
• The money invested by foreign institutional investors in the Indian stock market is showing an increasing
trend over the last decade.

Organization of Data
The data regarding cricket test matches can give access to lot of information, but we cannot get
quick answers for our specific queries. Its difficult to say which bowler has taken the maximum
or minimum wickets, who has scored the highest runs, etc. In order to get answers to all these
queries, one has to go through the data collected by the scorer or statistician. For example, let the
runs scored by different batsmen in test series be: 30, 86, 42, 115, 93, 17, 23, 55, 90, 10, 5, 41,
69, 102, 74, 118, 98, 4, 110, 13 and 7.