Your roommate is an only child.What percentage of people in developed countries has at least one sibling?

Question

Quizplus · Accepted Answer

According to a survey conducted by the Pew Research Center in 2015, about 80% of people in developed countries have at least one sibling. Therefore, option B is correct. Option A can be immediately eliminated as it is not possible for everyone in developed countries to be an only child. Option C and D may seem plausible, but they are either too high or too low as most people in developed countries have at least one sibling.

Your Roommate Is an Only Child