If and , then calculate the coefficient of variation.

Mean of 100 items is 48 and their standard deviation is 10. Find the sum of all the items and the sum of the squares of all the items.

The mean and standard deviation of 20 items are found to be 10 and 2 respectively. At the time of checking it was found that an item 12 was wrongly entered as 8. Calculate the correct mean and standard deviation.

Calculate the coefficient of variation of the following data: 20, 18, 32, 24, 26.

If the coefficient of variation of a collection of data is 57 and its S.D is 6.84, then find the mean.