I can't really see what any fuss is about.

If the OP asks for convert "1100110.11" to base 10 then seeing as how he has placed a decimal point there, he has clearlychosento treat the bits to the right of it as fractional places.

The answer of how to convert it is to treat each digit position as a power of two, assuming it is binary originally, and then sum them all up.

For a number where the digits are ...ABCDEFG.HI..., the answer is:

... A*2^6 + B*2^5 + C*2^4 + D*2^3 + E*2^2 + F*2^1 + G*2^0 + H*2^-1 + I*2^-2 ...

(where ^ denotes the power function)