The marks obtained (out of 20) by 30 students of a class in a test are as follows: 14, 16,
15, 11, 15, 14, 13, 16, 8, 10, 7, 11, 18, 15, 14, 19, 20, 7, 10, 13, 12, 14, 15, 13, 16, 17, 14, 11,
10, 20.
Prepare a frequency distribution table for the above data using class intervals of
equal width in which one class interval is 4 - 8 (excluding 8 and including 4).
Answers
In this table class intervals are such that Lower limit is included and upper limit is not included in the class.
That means In interval (4−8), 4 is included but 8 is excluded.
And for frequency we counted how many times number from the interval occurs in given data.
Class interval Frequency
4−8 2
8−12 7
12−16 13
16−20 6
20−24 2
Total 30
Given,
Number of Students = 30
Class Interval = 4-8
Given Data = 14, 16, 15, 11, 15, 14, 13, 16,8, 10, 7, 11, 18, 15, 14, 19, 20, 7, 10, 13, 12, 14, 15, 13, 16, 17, 14, 11, 10, 20.
To find,
Frequency distribution table for the above data
Solution,
We are given one interval i.e. is 4-8 in which 4 is included and 8 is excluded, so the width of the class interval is 4.
Class Interval Frequency
4-8 2
8-12 7
12-16 13
16-20 6
20-24 2
Total 30
Hence, the frequency distribution table for the above data is given above.