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.
Ritalin doesnât stay in the body for very long. The drugâs half-life is 3 hours at the most, meaning that Ritalin leaves the body within a few days. Can Ritalin show up on a drug test? NO, not on a standard 5 panel, but Ritalin can show up positive for a drug screen panel for amphetamines.