The number of students absent in a class were recorded every day for 120 days and the information is given in the following frequency table:
No. of students absent ($x$):  0  1  2  3  4  5  6  7 
No. of days ($f$):  1  4  10  50  34  15  4  2 
Find the mean number of students absents per day.
Given:
The number of students absent in a class were recorded every day for 120 days and the information is given in the frequency table
To do:
We have to find the mean number of students absents per day.
Solution:
Let the assumed mean be $A=3$
Number of students absent ($x_i$)  Number of days ($f_i$)  $d_i = x_i A$ $A = 3$
 $f_i \times\ d_i$ 
0  1  $3$  $3$ 
1  4  $2$  $8$ 
2  10  $1$  $10$ 
3 $A$  50  0  0 
4  34  1  34 
5  15  2  30 
6  4  3  12 
7  2  4  8 
Total  $\sum{f_i}=120$   $\sum{f_id_i}=63$

We know that,
Mean $=A+\frac{\sum{f_id_i}}{\sum{f_i}}$
Therefore,
Mean $=3+\frac{63}{120}$
$=3+0.525$
$=3.525$
The mean number of students per day is $3.53$.
 Related Articles
 On A Rainy Day Out Of 150 Students In A School 25 Were Absent. Find The Percentage Of Students Absent From The School. What Percentage Of Students Were Present?
 On a rainy day, 94 percent of the students were present in a school. If the number of students absent on that day was 174, find the total strength of the school.
 Out of 32 students, 8 are absent. What percent of the students are absent?
 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 students was absent.Number of days :0661212181824243030363642Number of students:101174431
 How to get the count of both present and absent students for a year in MySQL?
 The students of class VIII of a school donated Rs. 2401 for PM’s National Relief Fund. Each student donated as many rupees as the number of students in the class. Find the number of students in the class.
 The following table gives the number of boys of a particular age in a class of 40 students. Calculate the mean age of the students.Age (in years):151617181920No. of students:38101054.
 Out of 30 students in a class, 6 like football, 12 like cricket and remaining like tennis. Find the ratio of(a) Number of students liking football to number of students liking tennis.(b) Number of students liking cricket to total number of students."
 Find the mean from the following frequency distribution of marks at a test in statistics:Marks ($x$):5101520253035404550No. of students ($f$):15508076724539986.
 The students of class 8 of a school donated 2401â‚¹ in all, for Prime Minister 's National Relief Fund . Each student donated as many rupees as the number of students in the class. Find the number of students in the class.
 A labourer is engaged for 20 days on the condition that he will receive Rs. \(120 \) for each day he works and will be fined Rs.\( 10 \) for each day he is absent. If he receives Rs.\( 1880 \) in all, for how many days did he remain absent?
 The teacher distributes 5 pencils per student. Can you tell how many pencils are needed, given the number of students? (Use \( s \) for the number of students.)
 The following is the distribution of height of students of a certain class in a certain city:Height (in cms):160162163165166168169171172174No. of students:1511814212718Find the average height of maximum number of students.
 There are some students in the two examination halls A and B. To make the number of students equal in each hall, 10 students are sent from \( A \) to \( B \). But if 20 students are sent from \( \mathrm{B} \) to \( \mathrm{A} \), the number of students in \( \mathrm{A} \) becomes double the number of students in B. Find the number of students in the two halls.
 In Class 7, 48 students passed out of 70 students. What is the percentage of students passed?
Kickstart Your Career
Get certified by completing the course
Get Started