If the accelerometer measures an acceleration of -4 m/s^2 along the X-axis and 7 m/s^2 along the Z-axis, what is the total acceleration?

The total acceleration can be found using the Pythagorean theorem.
Total acceleration = √((-4)^2 + 0^2 + 7^2)
                                = √65 ≈ 8.06 m/s^2.