Question

Please help would mean a lot :?)

Answer 1

A I think I don't know what your doing

Answer 2

The answer is D

To find the mean of something, you have to add up all the numbers and then divide the sum by the amount of numbers you have.
$- 10 + - 30 + - 25 + 15 + 35 = \\ - 15 \\ - 15 \div 5 = 3$