Answer: I think it is -2.30
Factors of 9: 1; 3; 9
Factors of 36: 1; 2; 3; 4; 6; 9; 12; 18; 36
GCF(9; 36) = 9
Remember that the difference between census and a sample survey is that in a census you take all the people of population in consideration in the study, and in the sample survey you take a part of that population in consideration to survey.
SO here if you check the problem it says that "in a recent poll, Pew reserchers found that 47% OF AMERICAN ADULT RESPONDENTS"
that is the population of the study that you want to focus, but there are a billion of american adult in US right? so its impossible that this company Pow Research made a census if you consider that a billion of people in US is almost infinite number for a company with a finite number of employees.
Also remember that a company has a budget to consider every month or every year, so to make a census or a sample survey it takes time and money, just to survey 10 people in a streeth of US cost money so if you want to reduce cost you might need to do a sample survey instead of a census.