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.
Figure 1: Two-Step TST Testing. 1  For contacts of a person with infectious TB disease, retesting in 8â10 weeks after exposure has ended is indicated when the initial TST or IGRA result is negative. In contact investigations, retesting is not called two-step testing.