Frequency-distribution chart or Frequency distribution is a method to present raw data in the form, from which one can easily understand the information contained in the raw data.
The construction of a frequency-distribution from the given raw data is done by the use of the method of tally marks.
How to give tally marks .
BUT the 5th mark is drawn ACROSS the previous 4 marks:
Remember : every fifth mark is drawn across the previous 4 marks
Example 1 : Write 13 as tally mark.
Solution : 13 = 5 + 5 + 3 ( use of 5 )
13 =
Example 2 :Given below are the marks of 25 students of class 8th in a school. Prepare a frequency-distribution table.
15,16,16,14,17,17,16,15,15,16,16,17,15,16,16,14,16,15,14,15,16,16,15,14,15
Marks
Tally bars
Frequency
14
||||
4
15
8
16
10
17
|||
3
Total
-------
25
Range = Highest score - Lowest score
From the above , we can say that,
Highest score = 17 and Lowest score = 14 and so Range = 17 – 14 = 3
_________________________________________________________________ Example 3: Following table shows the points of scores each player plays :
Player
Game 1
Game 2
Game 3
Game 4
A
14
16
10
10
B
0
8
6
4
c
8
11
Did not play
13
1) Find the average scores of three players.
2) Who is the best performer?
Solution :
Average score of player A =( 14 + 16 + 10 + 10)/ 4 = 50 / 4 = 12.5
Average score of player B =( 0 + 8 + 6 + 4)/ 4 = 18 / 4 = 4.5
Average score of player C =( 8 + 11 + 13 )/ 4 = 32 / 3 = 10.66
So from above, the average score of player A is more.So player A is the best performer. Statistics