General DiscussionAbout Dota Open and Standard deviation.

This standard deviation is how much the average mmr of your game deviates.
At a 95% confidence level, the bound ≈ 2*std.dev.
Your estimated mmr is 3190mmr which approximately falls between the range of 1443.82 and 4936 at a 95% confidence level.

The confidence interval is very large
This means the prediction is still shit due to people not showing mmr (opendota uses shown mmr to calculated average mmr for games) or sample size trash, idk LUL.

Confidence interval has anything to do with MMR after calibrating ?
So approximately how much MMR will be

no, its current.
S.D high=unreliable.