data analysis and statistics

Table , Chart or Graph for Data Presentation

Data collection , processing to draw meaningful conclusions and presentation form the core of statistics , which is very vital part of our professional life . Normally , the raw data is very weird and jumbled It is very difficult to draw any meaningful conclusions from the raw data . Therefore , the data needs to be organized in a tabular form for easy processing to draw some meaningful conclusions . Besides , the data is presented in suitable graphical form for better presentation as it is said that A picture is worth

thousands of words . The first time ever , I was given an assignment in a Mathematics class to collect and organized the marks obtained by my classmates in Mathematics in last year 's examination using suitable tabular format and as a chart . The marks obtained by all 100 classmates of mine (including myself ) was collected . The same is presented in the appendix

It can be seen that the raw data is weird and it is very difficult to draw meaningful conclusions from the data . The minimum marks was 34 and the maximum marks was 97 . Therefore , the entire range was divided in 7 classes 30-40 , 40-50 , 50-60 , 60-70 , 70-80 , 80-90 and 90-100 . These classes were entered in first column . In the second column the mid point of the group was entered . In the third column , the number of students falling in each class was recorded . In the class 30-40 , the students scoring marks from 30 to 39 were counted . Those scoring 40 to 49 were counted in group 40-50 and so on

The frequency table is presented below

Class Interval Mid Point Frequency

30-40 35 5

40-50 45 13

50-60 55 18

60-70 65 17

70-80 75 31

80-90 85 14

90-100 95 2 From this frequency table , many useful conclusions can be drawn some of these are listed below

18 students failed in Mathematics

The mean score was calculated The tabulated data was presented as a polygon chart in figure 1 , below

This chart was prepared using MS excel . For this the mid point of the class range was taken as x-axis and the frequency of the class interval was taken as y-axis

From this graph it can be seen that most of the maximum number of students scores in the 70-80 range

Thus it can be concluded that from tabular and pictorial presentation it becomes very easy to grasp the data , which is otherwise very weird

Appendix

Marks obtained by my classmates including myself in mathematics in last year 's examination . Maximum marks 100 , Passing marks 50

34 , 70 , 71 , 75 , 68 , 75 , 59 , 65 , 67 , 82 , 55 , 65 , 67 , 78 , 79 , 81 , 80 , 74 74 , 85 , 87 , 78 , 77 , 72 , 67 , 77 , 56 , 55 , 87 , 72 , 88 , 65 , 66 , 43 , 45 , 81 83 , 65 , 67 , 81 , 82 , 76 , 75 , 75 , 72 , 73 , 65 , 67 , 77 , 75 , 85 , 87 , 34 , 36 37 , 45 , 46 , 46 , 48 , 49 , 51 , 53 , 54 , 55 , 58 , 92 , 93 , 76 , 74 , 76...