The T-Score Formula. The t-score is a fraction. The numerator is the sample's mean minus mean of the group you are comparing the sample to, and the denominator is the sample's standard deviation divided by the square root of the sample size.
If you have smoked marijuana then the drug will stay for 3 to 30 days. This is normal for the common drugs. But in the case of marijuana, this can be detected even after a month in Urine drug test marijuana. Marijuana will stay in your system for 10 days if you have been smoking occasionally.
How long does marijuana stay in your system if you only smoked it once in the past 2 years? Someone who smokes occasionally-or for the first time-will  likely test positive for 1-3 days afterward, according to a review  by the  National Drug Court Institute (â¦ NDCI).ow long does marijuana stay in your system of you smoked it once? Someone who smokes occasionally-or for the first time-will  likely test positive for 1-3 days afterward, according to a review  by the  National Drug Court Institute (â¦ NDCI).