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.
Before we understand the period of time that marijuana lasts in the system, there are a couple of facts that you should know. - The presence of marijuana is detected by a drug test through the presence of the active chemical THC or Tetrahydrocannabinol. Technically, what is detected is known as THC-COOH ...arijuana can stay in the urine for up to two months in cases of very frequent, prolonged use. Basically, the more you use marijuana, the longer it will remain in your urine. If you have just tried marijuana, for example, and that was your only use, it will probably be out of your urine within a week.