NEW YORK--(BUSINESS WIRE)--Fitch Ratings has affirmed the ratings for the student loan revenue bonds issued by Massachusetts Educational Financing Authority Issue K at 'Asf'. The Rating Outlook remains Stable. A full list of rating actions follows at the end of this release. KEY RATING DRIVERS Adequate Collateral Quality: The trust is collateralized by approximately $245 million of private student loans as of March 2015. The loans were originated under MEFA's Student Loan Program. The projected