Final answer:
The statement that a seismogram is the paper record of seismic waves recorded by a seismograph is true. P-waves and S-waves' arrival times, which travel at different speeds, allow calculation of the distance to an earthquake's epicenter. However, precision can be affected by uncertainties in seismic wave speeds.
Step-by-step explanation:
The statement is true: A seismogram is indeed the paper record on which seismic waves are recorded by a seismograph. Seismographs are designed to measure the arrival times of seismic waves with precision, typically to the hundredth of a second. The distance to an earthquake's epicenter can be calculated by analyzing the difference in arrival times between the faster P-waves (pressure waves) and the slower S-waves (shear waves).
Considering given speeds for P-waves of 7.20 km/s and S-waves of 4.00 km/s, an earthquake's epicenter distance can be determined with corresponding precision based on the time difference between these waves. However, this precision may be limited by any uncertainty in the waves' propagation speeds, which in turn affects the accuracy of locating earthquake epicenters or underground nuclear test sites.