Qusetion: It is shown that the population of New York City, NY is much greater than that of Irvington, NJ. Employment opportunities, malls, social activities and tourist sites in New York City are therefore more than that in Irvington. If attractiveness for New York and Irvington are therefore 1,600 and 160 respectively and if the calculated impedance of migration is known to be 1.57, based on Gravity-Based model, estimate.