Step 1 :The question is asking for the rat population in the year 2002 and 2018. The formula given is \(n(t)=78 e^{0.01 t}\) where \(t\) is measured in years since 2002 and \(n(t)\) is measured in millions.
Step 2 :To find the rat population in 2002, we need to substitute \(t=0\) into the formula because the year 2002 is the starting point.
Step 3 :Substituting \(t=0\) into the formula, we get \(n(0)=78 e^{0.01 \times 0} = 78\). So, the rat population in 2002 was 78 million.
Step 4 :To find the rat population in 2018, we need to substitute \(t=2018-2002=16\) into the formula because the year 2018 is 16 years after 2002.
Step 5 :Substituting \(t=16\) into the formula, we get \(n(16)=78 e^{0.01 \times 16} = 91.53\). So, the rat population in 2018 was approximately 91.53 million.
Step 6 :Final Answer: The rat population in 2002 was \(\boxed{78}\) million and in 2018 was approximately \(\boxed{91.53}\) million.