Image text transcribed for accessibility: Earthquakes produce two kinds of seismic waves: The longitudinal primary waves (called P waves) and the transverse secondary waves (called S waves). Both S waves and P waves travel through Earth's crust and mantle, but at different speeds; the P waves are always faster than the S waves, but their exact speeds depend on depth and location. For the purpose of this exercise, we assume the P wave's speed to be vp = 9860 m/s while the S waves travel at a slower speed of vs = 5190 m/s. Suppose a seismic station detects a P wave and then delta t = 65.8 s later detects an S wave. How far away is the earthquake center? Answer in units of km.