Question

Make a frequency table from the following:

Marks obtained	More than 100	More than 90	More than 80	More than 70	More than 60	More than 50	More than 40	More than 30	More than 20	More than 10	More than 0
Number of students	0	2	15	30	48	59	71	78	82	88	90

Answer 1

Given: More-than cumulative data (Marks obtained → Number of students):

More than 100 : 0

More than 90 : 2

More than 80 : 15

More than 70 : 30

More than 60 : 48

More than 50 : 59

More than 40 : 71

More than 30 : 78

More than 20 : 82

More than 10 : 88

More than 0 : 90

Step-wise calculation:

To get the frequency (number of students) in each class interval (0 – 10, 10 – 20, ..., 90 – 100) subtract successive “more than” cumulative frequencies:

0 – 10: (More than 0) – (More than 10) = 90 – 88 = 2

10 – 20: 88 – 82 = 6

20 – 30: 82 – 78 = 4

30 – 40: 78 – 71 = 7

40 – 50: 71 – 59 = 12

50 – 60: 59 – 48 = 11

60 – 70: 48 – 30 = 18

70 – 80: 30 – 15 = 15

80 – 90: 15 – 2 = 13

90 – 100: 2 – 0 = 2

Marks	No. of students
0 – 10	2
10 – 20	6
20 – 30	4
30 – 40	7
40 – 50	12
50 – 60	11
60 – 70	18
70 – 80	15
80 – 90	13
90 – 100	2
Total	90