size of the classes is a
3-8, 9-14, 15-20
Answers
Answer: The marks scored by 40 candidates in an examination (out of 100) is given below:
75, 65, 57, 50, 32, 54, 75, 67, 75, 88, 80, 42, 40, 41, 34, 78, 43, 61,
42, 46, 68, 52, 43, 49, 59, 49, 67, 34, 33, 87, 97, 47, 46, 54, 48, 45,
51, 47, 41, 43.
Prepare a frequency distribution table with the class size 10. Take the class intervals as (30 - 39), (40 - 49), … and answer the following question:
(a) Which class intervals have highest and lowest frequency?
(b) Write the upper and lower limits of the class interval 30-39.
(c) What is the range of he given distribution?
ANSWER:
The frequency distribution table for the given marks can be drawn as:
(i) The class interval (40−49) has the highest frequency and the class interval (90−99) has the lowest frequency.
(ii) In the class interval (30−39), the lower limit is 30 − 0.5 = 29.5 and the upper limit is
39 + 0.5 = 39.5.
(iii) The range of the given distribution is 97− 32 = 65.