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Delete - Last Modified By: bjo at 17/02/2015 6:18:28 PM
For an in-depth analysis and description of the 68-95-99.7 rule, check out this wiki page. Alternatively, you can find a youtube video here.
Edit Delete - Last Modified By: BJO at 19/02/2015 9:52:55 AM
68-95-99.7 type questions:
from 2010
from 2013