A parallel beam of ultrasound of intensity 
is incident normally on a muscle of thickness 
, as shown in the figure below.
The ultrasound wave is reflected at a muscle-bone boundary. The intensity of the ultrasound received back at the transducer is 
. Some data for bone and muscle are given in the table below.
The intensity reflection coefficient 
for two media having specific acoustic impedances 
and 
is given by
Calculate the fraction of the ultrasound intensity that is reflected at the muscle-bone boundary.
Calculate the fraction of the ultrasound intensity that is transmitted through a thickness of of muscle.
Use your answers in (a) and (b) to determine the ratio 
.
