If your goal is to maximize your wealth, and your mutual fund will continue to return 7.6%, making minimum payments on your loans is not rational. Consider one of the loans for ~$1000 at 4.55%. You could take $1000 and pay it off, and be clear of that debt. Or, over the course of the year, you could invest that $1000 in your mutual fund, earn $76 (=$1000*7.6%), use that to pay the interest on your student loan of $45.50 (=$1000*4.55%), and come out ahead by $30.50, on average. In other words, paying off that student loan costs you $32.50 this year. Paying off the lower interest loan will cost you even more, implicitly.
The only valid reasons I see to pay off the loan are
1) your mutual fund won't really return more than the interest on your loans (certainly possible--do you expect this?);
2) you attach some extra value to being debt-free. This is an individual judgement, but I'm strongly of the opinion that debt doesn't matter if as long as your assets are covering your payments.
At this point, I strongly regret having paid back my student loans as quickly as I did. Making minimum payments would've helped build my credit, give me tax savings and allow me to take advantage of further investment gains. I wasn't thinking clearly before.