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

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

The frequency distribution of the monthly incomes (in rupees) of the workers of a small industry are given below. Find the average of their incomes .

The frequency distribution of the degre of the drugs of 110 patients to be cured are given below : Here the number of patients being cured by taking 20 tablets and the number of patients being cured by taking 32 tablets are unknown. But it is known that the number of tablets required to be cured per patient is 20 tablets. Find the two unknown frequencies.

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

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.