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.

Question :

Number of days0 – 66 – 1010 – 1414 – 2020 – 2828 – 3838 – 40
Number of students111074431

Solution :

Here, the class size varies, and \(x_i\)’s are small,

Number of daysMid-Value (\(x_i\))Number Students (\(f_i\))\(f_iu_i\)
0 – 631133
6 – 1081080
10 – 1412784
14 – 2017468
20 – 2824496
28 – 3033399
38 – 4039139
Total40499

Let us apply the direct method here :

So, Mean = \(\sum f_iu_i\over \sum f_i\) = \(499\over 40\) = 12.475

Hence, mean = 12.48 days

Leave a Comment

Your email address will not be published.