Beginner Gardening: Dormancy rate? Germination rate?, 1 by Lumberjill

Lumberjill wrote:
I bought seeds, thinking I'd get 1/64 oz of reasonably viable seeds. The package arrived saying that over 1.5 years ago the seed tested 25% germination rate. But what does the dormancy rate mean? The seed company is telling me that I must add the germination plus the dormancy rates, to see that I really have 75% viable seeds. I've googled around, and it doesn't seem that dormancy rates should simply be added to germination rates. Can someone sort this out in simple terms for me?