Had to look for the options and here is my answer. Based on the given type of study above which would cover the residents of the City of Atlanta, the best design for this in order for the council to know if they support the beautification of the downtown area is a SURVEY. Hope this helps.
The value of t that makes the factor e^(.032t) have the value of 2 can be found using logarithms. 2 = e^(0.032t) ln(2) = ln(e^(0.032t)) = 0.032t t = ln(2)/0.032 ≈ 21.66
