A scientist wishes to determine how effective a vaccine is in protecting rats against a contagious disease. What experimental procedure should the scientist use to determine the vaccine's effectiveness?

Question

Ms. Sue · Accepted Answer

Shouldn't she vaccinate half the rats and then expose all of them to the disease?

nick · Answer

give vaccinations to 50 of the 100 rats and then expose all 100 to the disease

Samantha · Answer

Give vaccinations to 50 of the 100 rats and then expose all 100 to the disease

Iroda Juraeva · Answer

D) vaccinate 50 of the 100 rats and then expose only 50 vaccinated rats to the disease.

Kristin · Answer

Vaccinate 50 of the rats then expose only the 50 vaccinated rats to the disease