Question

Does consuming beer attract mosquitoes? Exercise 4.17 on page 268 discusses an experiment done in Africa testing possible ways to reduce the spread of malaria by mosquitoes. In the experiment, 43 volunteers were randomly assigned to consume either a liter of beer or a liter of water, and the attractiveness to mosquitoes of each volunteer was measured. The experiment was designed to test whether beer consumption increases mosquito attraction. The report \(^{30}\) states that "Beer consumption, as opposed to water consumption, significantly increased the activation \(\ldots\) of \(A n\). gambiae [mosquitoes] ... \((P<0.001)\)." (a) Is this convincing evidence that consuming beer is associated with higher mosquito attraction? Why or why not? (b) How strong is the evidence for the result? Explain. (c) Based on these results, it is reasonable to conclude that consuming beer causes an increase in mosquito attraction? Why or why not?

Short answer

While the experiment provides strong evidence associating beer consumption with increased mosquito attraction, it does not conclusively prove that beer consumption causes an increase in mosquito attraction.

Step-by-step solution

Interpreting the Evidence

The \(P<0.001\) indicates a significant correlation between consuming beer and attractiveness to mosquitoes. This means that the chance that the observed difference happened by chance is less than 0.1%. Therefore it is highly likely that beer consumption increases mosquito attraction.

Strength of the Evidence

The strength of the evidence is determined by the P-value. In this case, \(P<0.001\) is a very strong evidence against the null hypothesis. It indicates that, if there was no difference between beer drinking and mosquito attraction, the probability to observe such a difference as in the experiment is less than 0.1%.

Reasonability of Concluding Causation

While statistically significant, we cannot definitely state that beer consumption causes an increase in mosquito attraction just based on this experiment. Correlation does not imply causation. Other variables might be at play that were not accounted for in the experiment. More studies are needed to establish causation.