How will a particle system behave if it has a random start size and a linearly decreasing curve for size over lifetime?

If a particle spawns with a random size between 0.2 and 1, and the curve looks as follows:
100560-screen-shot-2017-08-23-at-101308-pm.jpg
What happens after the particle spawns? Will it start out at the point along the curve corresponding to its start size, and would it disappear faster than a particle that spawned with a larger size? Does it depend on its start lifetime as well? And what are the units for the horizontal axis on the size over lifetime curve?

Thank you for your help!

They just multiply. The horizontal axis in the curve scales with each particle’s start lifetime.