"Shifting" the binary representation of the decimal numbers 0 to 15 ?

Question

could someone help me with the following question

Tabulate the binary representation of the decimal numbers 0 to 15. If this binary representation is then “shifted” (i.e., AC coupled) so that 0 represents –Vdd/2 and 15 represents +Vdd/2, again, identify the “sign bit” and the most significant bit.

Any help would be appreciated, thanks. I do have the binary representation from 0 to 15 but i dont understand the rest.

0000

0001

0010

0011

0100

0101

0110

0111

1000

1001

1010

1011

1100

1101

1110

1111

Answer 1

the sign bit is always the MSB, and a "1" indicates negative. So in the case of "0111" the sign bit is "0" so its a positive number (+7). for

"1111" the sign bit is "1" so its negative (-7).

so the first bit is the sign bit and I think they are thinking the second bit would then be the MSB of the number.