You are the city planner in charge of running a high-efficiency power line from a power station to a new shopping center being built nearby. The power station is located on 1st St, and the shopping center is on Shopping Ln. The power station is 10miles north of Shopping Ln, and the shopping center is 7 miles east of 1st St. While the power line can run above ground on 1st St, it must be run underground away from 1st St. The cost of running the power line some distance underground is three times that of running the power line the same distance above the ground. How far from the Power Station should the wire switch from running above ground (i.e., along 1st St.) to running below ground