The following table shows the cumulative frequency distribution of marks of 800 students in an examination:
Marks | Number of students |
Below 10 Below 20 Below 30 Below 40 Below 50 Below 60 Below 70 Below 80 Below 90 Below 100 |
10 50 130 270 440 570 670 740 780 800 |
Construct a frequency distribution table for the data above.
Solution. Frequency distribution: It tells how frequencies are distributed over values in a
frequency distribution. However mostly we use frequency distribution to summarize categorical variables.
Marks | cf | f |
0-10 | 10 | 10 |
10-20 | 50 | 50-10=40 |
20-30 | 130 | 130-50=80 |
30-40 | 270 | 270-130=140 |
40-50 | 440 | 440-270=170 |
50-60 | 570 | 570-440=130 |
60-70 | 670 | 670-570=100 |
70-80 | 740 | 740-670=70 |
80-90 | 780 | 780-740=40 |
90-100 | 800 | 800-780=20 |