Variance % = 1.3%

[tdu2000]

Hello:

First, hope I understood variance correctly.

The variance % of a diamond of diameter measurements 6.47mmx6.56mm is: 0.0138 or 1.38%?
(((6.56-6.47 / (6.47+6.56)/2)))

Anyway, should I be alarmed by this value?

Thanks