It means that the material does not meet at least one of the requirements in terms of its quality.
Sub means smaller or under.
An estimate for the mean of a set of observations is just that - an estimate. Another set of observations will give a different estimates. These estimates for the mean will have a distribution which will have a standard error. If you have two sub-populations, the mean of each sub-population will have a standards error and the se of the difference between the means is a measure of the variability of the estimates of the difference.A typical school work example: the heights of men and of women. There will be a mean height for men, Hm, with a se for men's heights and a mean height for women, Hw, with its own se. The difference in mean heights is Hm - Hw and which will have an estimated se.
no the standard deviation is not equal to mean of absolute distance from the mean
The mean of a standard normal distribution is 0.
It means that the material does not meet at least one of the requirements in terms of its quality.
rivets
You make a good point, it is a strange one. But in this context par is meant to mean, the average, of the usual quality etc, so below par essentially means sub standard, and has nothing to do with golf.
under a foundation of a sub.
It means if you are a sub, your substiuting.
Moscow
i'm sure that it is rivets
drive-by media
Rivets
The word "submarine" is an example of a word with the prefix "sub."
Sub means smaller or under.
"Sub" in Spanish can have different meanings depending on the context. It can mean "under," "below," "beneath," or "since."