A class teacher has the following absentee record of 40 students of a class for the whole term. Find the mean number of days a student was absent.
Number of days
0 − 6
6 − 12
12 − 18
18 − 24
24 − 30
30 − 36
36 − 42
Number of students
10
11
7
4
4
3
1
Answers
Answered by
27
xi
3
9
15
21
27
33
39
fixi
30
99
105
84
108
99
39
sigma fixi=564
fi=40
mean = 564/40=14.1
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