Page 105 - Ganit Kaushal
P. 105

the game’ (known as ‘variable’), second for the ‘tally-marks’ and third for the ‘number of students’ (known
                  as ‘frequency’ of the variable) as shown in the table below.

                          Game (Variable)                   Tally marks                 Number of students (Frequency)

                               Cricket                          |||| |                               6

                              Hockey                            |||| |||                             8
                              Kabaddi                           ||||                                 5

                                Pittu                           ||||                                 5
                             Badminton                           ||                                  2

                              Football                          ||||                                 4

                               Total                                                                 30
                  In the first column, we have put the names of the variables, which are Cricket, Hockey, Kabaddi, Pittu,
                  Badminton, and Football.

                  In the second column, a vertical bar (|) called a tally mark is put against the name of the game (variable)
                  whenever it occurs. If a particular variable occurs more than 4 times, we represent it by cutting the first four tally
                  marks horizontally (or diagonally); this gives us a block of five (|||| or  ). The first four tally marks are entered
                  by vertical bars. The fifth tally mark is entered by cutting the first four tally marks (horizontally or diagonally).
                  In the third column, we write the frequency of each variable (observation). Frequency is a number that tells
                  us how many times a particular observation occurs in a given set of data, e.g., Cricket has occurred 6 times in
                  the above data. So, 6 is the frequency of Cricket in the above data.

                  That’s why the above table is also called the frequency distribution table.
                  Now, the raw data collected by Navya has been put in an organised manner with the help of tally marks in the
                  above table. So, it is easily understandable, and you can answer any question associated with the data collected
                  by Navya. Here are a few:
                          What is the most popular game among Navya’s classmates?

                          Hockey. That’s right!
                          What is the second most popular game in her class?
                          Cricket. Right again!

                          How many students play badminton?
                          2. Perfect!
                          What is the least preferred game of Navya’s class?
                          Badminton. That’s great!

                  Now let’s have one more example of raw data of marks obtained (out of 10) by 30 students in class-VI, as
                  given below.

                                7       6       2        5       3        4       0       8        9       1
                                4       9       3        7       2        5       6       9        4       6
                                5       7       2        3       1        4       2       9        6       9



                                                                                   Data Handling and Presentation     103
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