To find the mean of a group of data, you add up all of the numbers and divide the total by the amount of numbers there are. In this case, you have 15,11,10,11,14,10,15,10,and 12.
subtract the number 3 5 and 8 then combine like terms and 8 on both sides of the equation then simplify after that divide both sides of the equation by the same term then simplify