Find the arithmetic mean of the sales per day in a fair price shop in a week.

Rs. 10000, Rs. .10250, Rs. .10790, Rs. .9865, Rs. .15350, Rs. .10110

If the mean of a set of observations x₁, x₂, ...., ...., x₁₀ is 20. Find the mean of x₁ + 4, x₂ + 8, x₃ + 12, .... ...., x₁₀ + 40.

Two years ago the mean age of 40 people was 11 years. Now a person left the group and the mean age is changed to 12 years. Find the age of the person who left the group.

Find the sum of deviations of all observations of the data 5, 8, 10, 15, 22 from their mean.

Arithmetic mean of nine observations is calculated as 38. But in doing so, an observation 27 is mistaken for 72. Find the actual mean of the data.

Marks of 12 students in a unit test are given as 4, 21, 13, 17, 5, 9, 10, 20, 19, 12, 20, 14.

Assume a mean and calculate the arithmetic mean of the data. Assume another number as mean and calculate the arithmetic mean again. Do you get the same result? Comment.

Mean of eight observations is 25. If one observation 11 is excluded, find the mean of the remaining.

Find the arithmetic mean of the sales per day in a fair price shop in a week.

Rs. 10000, Rs. .10250, Rs. .10790, Rs. .9865, Rs. .15350, Rs. .10110

Find the mean of the data;10.25, 9, 4.75, 8, 2.65, 12, 2.35

Five years ago mean age of a family was 25 years. What is the present mean age of the family?

The sum of deviations of ‘n’ observations from 25 is 25 and sum of deviations of the same ‘n’ observations from 35 is − 25. Find the mean of the observations.