In a school, no student has score less than 25 mark or more than 60 marks in exam. Their CF are as follows.
Less than
60
55
50
45
40
35
30
Total freq.
120
115
90
75
65
45
Answers
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In a school, no student has scored less than 25 marks or more than 60 marks in an examination. Their cumulative frequencies are as follows:
Less than = 60 55 50 45 40 35 30
Total frequency = 120 115 90 75 65 45 32
Find the frequencies in the class intervals 25−30, 30−35,....55−60.
Step-by-Step Explanation:
To find: Find the frequencies in the class intervals 25−30, 30−35,....55−60.
Given,
Marks Cumulative Frequency
Less than 60 120
Less than 55 115
Less than 50 90
Less than 45 75
Less than 40 65
Less than 35 45
Less than 30 32
The simple frequency distribution in class interval can be represented in the form:
Marks Number of Students
25 − 30 32
30 − 35 45 − 32 = 13
35 − 40 65 − 45 = 20
40 − 45 75 − 65 = 10
45 − 50 90 − 75 = 15
50 − 55 115 − 90 = 25
55 − 60 120 − 115 = 5