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 question usually refers to how soon after exposure can someone test for HIV. This usually requires waiting 3 to 4 weeks before taking an antibody-based test (see Figure 6). UK guidelines state that 4th generation HIV tests (antigen/antibody) will detect 95% of infections four weeks after exposure. A negative test after four weeks then needs to be confirmed with a second test three months after the risk. This is in case you take longer than four weeks to generate an antibody response.