Moving on to Zone 2, we apply the same gravity model principles to determine where its 2,000 produced trips are going.First, let's look at the denominator, which represents the total accessibility for trips starting in Zone 2. Because Zone 2 has zero attraction (A 2 = 0), the middle term of our sum drops out. We are left with the attraction of Zone 1 (2000 times 0.063) plus the attraction of Zone 3 (5000 times 0.063), giving us a total denominator of 441.7.Now, to find trips from Zone 2 to Zone