Binary Data encoding and decoding format
It's equivalent to a conventional binary representation except that the final value is scaled.

In the example they set the value of the LSB to 0.1, so the next bit has value 0.2, then next 0.4, 0.8, 1.6, 3.2, ... and so on. This is equivalent to decoding the binary as an unsigned integer in the usual way (bit values 1, 2, 4, 8, ...) and then multiplying the result by 0.1.

9B is 155 in decimal, so the intended value is 155 * 0.1 = 15.5.