How to convert 4.6-10.5 micrograms/dL to nmol/L? The answer is 59-135 nmol/L, but I have no idea how to set it up to get that answer.

There are two problems with this problem.

1. First, you can't convert mass of anything to mols of that without knowing what it is.
2. You symbolism leaves something to be desired. Is that 4.6E5(4.6 x 10^5) or something different. I don't know what to do with the - sign and the 10.5. Also I don't know how to interpret 59-135.