The mean of a set of numbers is found by adding all of the numbers together and dividing the total by the number of numbers in the set. To find the mean of the set of numbers 6, 12, 10, and 8, we would first add the numbers together to get a total of 36. Since there are 4 numbers in the set, we would then divide 36 by 4 to get the mean, which is 9. Therefore, the mean of the set of numbers 6, 12, 10, and 8 is 9.