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A data matrix consisting of marks obtained by students in half-yearly exam will look as follows:
English Mathematics Physics Chemistry Computer Science
Student Theory ASL Tot Theory Prac Tot Theory Prac Tot Theory Prac Tot Theory Prac Tot %
Name age
[80] [20] [100] [80] [20] [100] [70] [30] [100] [70] [30] [100] [70] [30] [100]
A 70 18 88 66 17 83 13 24 37 47 28 75 41 19 60 68.6
B 68 15 83 43 12 55 35 23 58 37 20 57 21 18 39 58.4
C 62 17 79 56 13 69 21 25 46 36 22 58 42 19 61 62.6
D 70 18 88 79 20 99 62 28 90 68 29 97 63 25 88 92.4
E 68 16 84 34 11 45 27 23 50 41 28 69 23 19 42 58
F 71 17 88 75 20 95 57 27 84 66 27 93 65 26 91 90.2
G 67 16 83 50 14 64 29 24 53 43 25 68 31 20 51 63.8
H 69 15 84 54 17 71 35 26 61 46 27 73 50 22 72 72.2
In the above example, student name, English theory marks, ASL marks, etc. are variables and each row represents a
single case (student).
Frequency Tables
The frequency of a particular data value is the number of occurrences of that data value in a dataset. Let's say that if five
students achieved 95 marks in the maths exam, then the score of 95 has a frequency of 5.
The frequency of a data value is often represented by 'f'. A frequency table is created by ordering the collected data
values in ascending order of magnitude or in descending order with their respective frequencies.
Example 1: The following shows the number of chocolates eaten by students of a class on a particular day. Create a
frequency table for this data:
6 3 2 1 3 2 5 6 2 2
4 4 1 3 1 6 3 1 2 6
2 4 5 5 4 5 6 3 5 4
The frequency table of the above data is as follows:
Chocolates Tally Frequency
1 //// 4
2 / 6
3 //// 5
4 //// 5
5 //// 5
6 //// 5
Total 30 30
Example 2: The following shows marks scored by XI class students in the Physics Half Yearly exam. Create a frequency
table for this data.
37 58 46 90 50 84
53 61 44 38 54 57
59 19 89 49 66 50
53 81 63 48 71 51
52
Data Analysis (Computational Thinking) 255

