Organizing Data

Organizing Data

The collected data are to be arranged methodically or logically so that the information can be looked up fast whenever needed, easily and efficiently. The method of organizing the data is discussed as follows.

1. Tally Marks

Consider the data collected by Santhi (given in Table:5.1). Is it easy to get the required information from the data? For example, can any one quickly tell the number of people who do not like Laddu? No. So she decides to organize the data (See Fig. 5.3 (a)).

Her friends come to help her. Malar arranges the data a given below in the table. She uses ‘✓’ marks to note down how many friends like each of the sweets. The count of each sweet is called as “Frequency”.

But, Rahim arranges the data as shown below.

See that, it does not matter whether you use ‘✔’ or ‘|’.

Both have done well. But one would prefer tally marks as they are very simple.

So, the teacher arranges the data as follows:

This looks so much easier to read now.

The standard form of representing the data is got by using ‘Tally marks’.

Note

* The occurrence of each information is marked by a vertical line ‘|’.

* Every fifth tally is recorded by striking through the previous four vertical lines as ‘ ’.

* This makes counting up the tallies easy.

Example 5.1

Thamarai is fond of reading books. The number of pages read by her on each day during the last 40 days are given below. Make a Tally Marks table.

1 3 5 6 6 3 5 4 1 6 2 5 3 4 1 6 6 5 5 1

1 2 3 2 5 2 4 1 6 2 5 5 6 5 5 3 5 2 5 1

Solution

The Tally marks table is given below.

Think

If someone asks, “typically, how many pages does Thamarai read in one day?”, what will be your answer?

ICT Corner

STATISTICS

Expected Result is shown in this picture

Step – 1

Open the Browser and copy and paste the Link given below (or) by typing the URL given (or) Scan the QR Code.

Step − 2

GeoGebra worksheet “Tally Mark Addition” will appear. You can generate a new set by clicking “Click here to generate a new set”.

Step-3

Select “Show Answer” check box to view the answers for the sets.

Step 4:

Generate various results and observe the difference in set formation

Geogebra’s url :

https://www.geogebra.org/m/gzRAnHKw

Alternate source to try tally calculations:

https://play.google.com/store/apps/details?id=org.geogebra&hl=en