Step 1 :The problem is asking for an explicit formula for an exponential growth model. The formula for exponential growth is generally given by \(P_n = P_0 * r^n\), where \(P_0\) is the initial population, \(r\) is the common ratio, and \(n\) is the number of time periods.
Step 2 :In this case, \(P_0 = 4\) and \(r = 1.35\). We can substitute these values into the formula to find \(P_n\).
Step 3 :The explicit formula for \(P_{n}\) is \(P_{n} = 4 * 1.35^n\).
Step 4 :After finding the formula for \(P_n\), we can substitute \(n = 12\) to find \(P_{12}\).
Step 5 :Using this formula, \(P_{12}\) is approximately \(\boxed{146.6}\).