You wish to find the spring constant k for a particular spring. To do this, you suspend the spring vertically, and first attach a "pre-load" mass (m = 99.6 g) to the end of the spring, causing it to stretch a bit (this allows the spring to be in its linear regime, so that the force is described by Hooke's Law, F = -kx). Then, you attach a second mass (m = 100.2 g) and observe that the spring stretches a further 7.52 cm. What is the experimentally determined spring constant?