Question

a class teacher has the following attendance record of ticket of 40 students of the class for whole term find the mean number of days a study was percent out of 56 days in the term
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Answer 1

Answer:

To find the class mark (x

i

) for each interval, using the following relation:

(x

i

)=

2

Upperclasslimit+Lowerclasslimit

Taking 17 as assumed mean (a), calculating d

i

and f

i

d

i

as:

From the table:

∑f

i

=40

∑f

i

d

i

=−181

Mean,

x

ˉ

=a+

∑f

i

∑f

i

d

i

=17+(

40

−181

)

=17−4.525

=12.475

≈12.48

Therefore, the mean number of days =12.48 days for which a student was absent.