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.
Various studies have shown that amphetamines/methamphetamines remain in the saliva in sufficient quantities for detection for up to 50 hours; cocaine can be detected for up to 12-36 hours, opiates for up to 24 hours and longer, and cannabinoids for up to 24 hours.n general detection of drugs in oral fluid ranges from within minutes of consumption up to 2-3 days. Available research indicates on that marijana (THC-delta 9) can not be detected beyond 18-24 hrs. in oral fluid at ng/ml levels, regardless of the test / test technique.