Question

question 16

cal studies the effects of a new vaccine and designs an experiment with two groups. group a gets the vaccine and group b gets a placebo shot.

which of the following would be the null hypothesis in cals experiment?

• group b is less likely to contract the virus compared to group a.
• group a is less likely to contract the virus compared to group b.
• group a and group b are both less likely to contract the virus.
• group a and group b are equally likely to contract the virus.

Explanation:

Define the null hypothesis concept

Using the Null Hypothesis knowledge point

The null hypothesis (\(H_0\)) is a statement of no effect, no difference, or no relationship between variables. In an experimental setup comparing two groups, it posits that any observed differences are due to random chance rather than the experimental treatment.

Apply the concept to Cal's experiment

Using the Null Hypothesis knowledge point

Cal's experiment compares Group A (vaccine) and Group B (placebo). The null hypothesis must state that there is no difference in the likelihood of contracting the virus between the two groups:

$$ H_0: \text{Likelihood(Group A)} = \text{Likelihood(Group B)} $$

This corresponds to the statement that Group A and Group B are equally likely to contract the virus.

Answer:

• (A) Group B is less likely to contract the virus compared to Group A.
• (B) Group A is less likely to contract the virus compared to Group B.
• (C) Group A and Group B are both less likely to contract the virus.
• (D) Group A and Group B are equally likely to contract the virus. (Correct answer)