Page 74 - Concepts of Reasoning-8

CHAPTER

Worksheet-15.1 Statistics 15

Frequency Distribution, Grouping of Data

1. The marks obtained by 50 students in an exam are as follows :
45 97 64 52 32 73 82 54 61 98
81 73 68 35 51 36 33 77 93 46
56 42 54 83 45 49 44 92 85 59
65 33 93 41 77 51 81 67 71 94
99 69 71 94 88 97 93 84 39 98
Prepare the frequency distribution table for the above data by taking the class size as 10. One row is
done for your reference. Answer the questions given below the table.

Marks obtained by students Tally marks Frequency
30 – 40 6
40 – 50
50 – 60
60 – 70
70 – 80
80 – 90
90 – 100
Total

a. The lower limit of the class interval 70-80 is __________ .
b. The frequency of the students who secured 70-90 marks is __________ .
c. Class mark of the class interval 80-90 is __________ .

d. Range of the marks obtained by the students in the given data is __________ .
2. Observe the frequency distribution table prepared for the data given below : Circle the error and
correct it in the table given.
The age distribution of 30 people who are covered by medical insurance is as follows :
33 64 53 52 32 73
28 73 68 37 51 36
56 42 54 74 45 29
62 30 69 40 57 48
29 69 70 42 29 43
Given frequency table Corrected table
Ages Tally marks Frequency Ages Tally marks Frequency
25 – 35 6
35 – 45 6
45 – 55 3
55 – 70 5
70 – 75 7
Total 27

74 Reasoning - 8