6 is the mean for dataset 2, 4, 6, 8 & 10 from which the standard deviation about to be measured to estimate the common variation of the sample or population dataset from its central location.
to find the mean, you must add all the numbers together and divide by the amount of numbers. for example, 2+4+6+8+10=30. next, you divide 30 by the amount of numbers, which is 5. if you count there are five numbers. so 30÷5=6 :)
