Please help me understand this question.

Can a hypothesis test yield a statistically significant (say p<=0.05), yet practically meaningless result? Give an example of how this might happen.

With larger samples, results might be statistically significant, but not practically significant. For example, heights of people are significantly greater as you find them higher on the executive ladder. However, the differences are only small fractions of an inch, which does not allow for accurate prediction in real life. (Even so, I cannot cite the study for you.)