The mean and standrad deviation of 100 items are 50, 5 and that of 150 items are 40, 6 respectively.
What is the combined mean of all 250 items?

The mean and standrad deviation of 100 items are 50, 5 and that of 150 items are 40, 6 respectively. What is the variance of all 250 items?

The mean and standrad deviation of 100 items are 50, 5 and that of 150 items are 40, 6 respectively. What is the combined standard deviation of all 250 items?

Mean and standard deviation of 100 items are 50 and 4 respectively. The sum of all squares of the items is

Mean and standard deviation of 100 items are 50 and 4, respectively . Find the sum of all the item and the sum of the squares of 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 . Calcualte the correct mean and standard deviation.

If mean and standard deviation of 100 items are 50 and 4 respectively the find the sum of all the item and the sum of the squares of item.