sample rate is 44.1kHZ Bits per sample is 16 so BPS Will be 2*16*44100 which leads 1411.2 KBPS
A ratio is simply one quantity divided by another quantity, assuming both quantities are expressed in the same units.
CD audio does indeed provide two stereo 16-bit samples 44100 times per second, for a total of 1411200 bits per second. This is accompanied on disk with a header, but this is usually very small compared to the audio data.
At 96 Kbps, an MP3-format compressed audio file can be assumed to use 96000 bits per second.
Dividing one by the other gives a compression ratio of 14.7:1.