You are asked to purify protein from a sample containing a mixture of proteins.

This protein has a molecular weight of 17,380 Daltons.

After adding Blue-dextran and DNP-aspartate to your mixture, you run it into a Sephadex-G75 column and collect 20 fractions.

Blue-dextran elutes in fraction #3, while DNP-aspartate elutes in fraction #18. In which fraction number would you expect to have eluted your protein? Clearly explain your answer and show all the necessary calculations.