Find the mean of the integers 5,-7,12,-10,15

The mean is found by summing the numbers up and dividing that sum by how many terms were in the set originally

we count 5 numbers

the sum is 5-7+12-10+15=-2+2+15=15

the sum divided by the number of numbers is the mean

15/5=3

the mean is 3

= 5 + (-7) + 12 + (-10) + 15

= 32-17

= 15

15/5 = 3