What is the %w/w of MgSO4 in the mixture?

A 0.455 g sample of a mixture of MgSO4 (fw 120.4) and K2SO4 (fw 174.3) was reacted with excess BaCl2 (fw 208.2) solution. The Ba2+ precipitates out all the SO42- from the MgSO4-K2SO4 mixture as BaSO4 (fw 233.4). 0.755 g of BaSO4 was collected.