Stem-and-Leaf plot is a method of organizing numerical data in order of place value. The 'ones digit' and the 'tens digit and greater' of each data item is separated as leaves and stems respectively. The stem-and-leaf plot below shows the number of students enrolled in a dance class in the past 12 years.
Vaccination with live viruses may interfere with TST reactions. For persons scheduled to receive a TST, testing should be done as follows: Either on the same day as vaccination with live-virus vaccine or 4-6 weeks after the administration of the live-virus vaccine. At least one month after smallpox vaccination.
This skin test should be read in 48-72 hours. If it is negative, you should repeat this process three months after the exposure. If you are exposed to someone with infectious tuberculosis and have had a positive reaction to the TB skin test in the past, you should not repeat it since it should still remain positive.f you are exposed to someone with infectious tuberculosis and have never had a positive reaction to the tuberculin (TB) skin test, you should have a baseline test within 3 months prior to the exposure date.