The half-life of a certain tranquilizer in the bloodstream is 39 hours. How long will it take for the drug to decay to 95% of the original dosage? Use the exponential decay model, A= Ao e kt, to solve. | hours (Round to one decimal place as needed.) 12.57 A logistic growth model for world population, f(x), in billions, x years after 1962 is f(x) = - this model, when will the world population be 8 billion? 1 +4.11 e -0.026x According to . According to this model, the world population will be 8 billion in (Round to the nearest whole number as needed.)