A survey of address changes filed with post offices and driver's license bureaus over the last ten years has establis...

Irina on September 9, 2019

@alva,

Great question. Notice that the data provided in the stimulus is a household data - twice as many households moved out of the city compared to households that moved in. The argument then concludes that the census that uses individual data, i.e. counts all residents, will show that the population has declined. Since we have no information on the size of the households that move in/ out - it could be a single person household or a family with 5 kids - for the conclusion to be true, the household size of residents moving in cannot be 2x or more the average household size of the residents moving out. Think about it, if all the households moving out were single person households and all households moving in 3 person households, the census would show population growth rather than decline. The question asks us which of the following statements would strengthen the argument.

(D) tells us that the average household size of people moving out is higher that the average household size of people moving in or staying - family with children, household size 3+ versus older people who live alone, size 1. Since this fact confirms our assumption, it strengthens the overall conclusion of the argument.

(E) tells us that people moving out are young adults looking for a career elsewhere, whereas people remaining or moving in had longstanding jobs (not sure how adults moving in could have longstanding jobs but that's a separate issue). (E) fails to tell us anything about the household size - it is tempting to infer that young adults moving out are single and people staying/ moving in moving as a family, then this scenario would actually weaken the argument. The bottom line is without additional information regarding the household size, (E) has no impact on the argument.

Does this make sense?

Let me know if you have any further questions.