Question

Suppose you want to determine how effective a new vaccine is at protecting monkeys against infection with Virus X. So, you gather two groups of monkeys; each group consists of 50 monkeys. You administer the test vaccine to one of the groups (Group A). The other group (Group B) receives saline solution, instead of vaccine. Next, you expose both groups to Virus X. You find that 60% of the of the monkeys in Group A end up showing symptoms of viral infection. In Group B, 65% of the monkeys end up showing symptoms of viral infection.

A) What's the independent variable in this experiment?
B) Is the independent variable quantitative or qualitative?
C) What's the dependent variable in this experiment?
D) Is the dependent variable quantitative or qualitative?
E) Based on your data, would you conclude that this new vaccine is effective at protecting monkeys against infection with Virus X? Why or why not?

Answer 1

The vaccine, an ancient-fashioned formulation composed of a synthetically acellular variant of the virus, did not produce unpleasant side effects in monkeys.

Explanation:

(a) The vaccine and saline answer used only to treat virus X infection in two groups of monkeys are variables in the study.

(b) The objective variables of the study are subjective, but not qualitative.

(c) The number of monkeys in each separate group who end up displaying signs of viral infection is the explanatory variable; 60 percent of monkeys in group A and 65 percent in group B.

(d) The dependent variables of the experiment are measurable as they indicate a quantifiable amount of healed monkeys.