Question

Pew Research Center conducted a poll in January 2018 asking people "How much help does the federal government provide to elderly people? Not enough, about the right amount, or too much?". The study attempted to contact 1750 people using random-digit-dialing, but was only able to collect responses from 1503. Pew Research Center notes that these results should only be generalized to US adults with telephones. Do you agree or disagree with that statement?

(A) Disagree. This survey suffers from selection bias.
(B) Agree. This is an unbiased sampling method and therefore generalizes to the population of interest.
(C) Disagree. This survey suffers from response bias.
(D) Disagree. This survey suffers from non-response bias.

Answer 1

(B) Agree. This is an unbiased sampling method and therefore generalizes to the population of interest.

Explanation:

As the study attempted to contact 1750 people using random-didit-dialing, this means that the survey aimed for adults with telephones, and the results provided by the company state that the results should only be generalized to US adults with telephones, and as they used randomized method to digit dial, they can be sure that they are very close to a sample that is random and unbiased. The only biased that the survey could have is that is leaving out adults without a telephone, but it states in the results that they are taken out, so it´s perfectly done and stated in teh results.