The average of weights (in kg) and the number of students of a school of given below. Find their collective average.

The weights (in Kg) and their frequency distribution of 100 students are given below. Find their arithmetic mean.

The marks obtained by 30 students in a examination of a class are given below . Find their average.

The arithmetic mean of the marks obtained in 8 different subjects in a school are given below. Find the average of the sum of the marks of 8 subjects.

Find the average height of the students from the given table.

Donations (in rupees) are given for a fare by the 100 students of a school. In the following table rate of donation and the number of students are given. In the above data, the rate of donation of 24 students is unknown , but it is known to us that the average rate of donation is Rs. 1.27 . Find teh unknown frequency.

The frequency distribution of the heights (in cm) of 100 students of class X in a school .Find the average height of the students .

The donations given to an orphanage home by the students of different classes of a secondary school are given below. Find the mean, median and mode of the data.

In a telephone exchange , the frequency distribution of the number of telephone calls per minute for any hour are given below : find the average number of telephone calls.

If in praxis Business school 40 students like chocolate while 30 like cake,if there are 10 students who like both and an equal number of students who like none of them. Find the total number of students at Praxis Business school.

The number of students in a class is 60 . The average of the ages of the boy-students is 14.5 years and the average of the ages of the girl-students is 16 years . If the collective average of the total students be 15 years , then find the number of boy-students and the number of girl-students.