Medical ultrasound may be used to locate a tumor in an organ such as the liver. The figure shows an ultrasonic beam that travels through a surrounding medium, refracts into the liver, reflects off the tumor, and refracts back into the surrounding medium. If the speed of the ultrasonic beam as it travels through the liver is \( 9.3 \% \) less than when it is traveling through the surrounding medium, determine the depth of the tumor (in cm ).