spell crit stacking for multi-element spells

How does spell crit from individual elements, between gear and enhancements, stack for multi-element spells, such as meteor swarm?

Are contributions from gear and enhancements summed down their respective element first, then the greater of the two elements taken and applied? Or is the greater of the two elements from gear summed with the greater of the two elements from enhancements?

Given this hypothetical situation, what would my effective total crit chance and crit multiplier be for meteor swarm?:

From enhancements, I have 4% Fire crit chance, and +0.0 Fire crit multiplier.

From enhancements, I have 8% Force crit chance, and +0.55 Force crit multiplier.

From gear, I have 9% Fire crit chance, and +0.5 Fire crit multiplier.

I have no arcane lore.

If I had kinetic lore, it would not apply (right?).

From my memory of an old wiki article (that I can't find now and may not even apply anymore), I think I would have a total of 17% crit chance (9 gear and 8 enh) and x2.55 multiplier (1.5 base + 0.5 gear + 0.55 enh). Is this right?