A student was given 2.89 g of a mixture containing anhydrous MgCl2 and KNO3. and had to quantify the amount of MgCl2 in the mixture. The student uses excess AgNO3 (aq) to precipitate the chloride ion as AgCl(s), and finds the mass of the AgCl precipitate to be 5.32 g. Calculate the mass percentage of MgCl2 in the original mixture. (Atomic masses should be taken as per the data given.)