The frequency distribution of the family members of 65 families are given below. Find the arithmetic mean.

The frequency distribution of the diameters (in mm) of 80 pipes are given below. Find their arithmetic mean, assuming 22 as the origin.

The frequency distritubution of the monthly salaries of 80 workers of a company are given below. Find the arithmetic mean of the salaries of the workers

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

The frequency distribution of the marks obtained in a school is given below. In the table, the number of students who obtained marks from 31 to 40 , is unknown . But it is known that the average of total work obtained by the students is 42.85. Find the lost frequency.

The frequency distributions of the weekly wages of some labourers of an industry are given below : The number of labourers having Rs. 25 weekly wages is unknown. But it is known that the average weekly wages of a labourer is Rs. 27.50 . Find the unknown frequency .

The step frequency distribution table of the marks obtained by female students is given below. Calculate the mean marks.

In a business hourse, the weekly salaries of 30 employees are given below : Find the arithmetic mean of the bonus of the employees.

The frequency distribution of the number of accidents in 30 consecutive days in a city are given below. Find the arithmetic mean.

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.

The frequency distributions of the quantity (in quintals) of producing cokes from a coke mine in 100 days are given below. Find the arithmetic mean.