Naturally occurring magnesium has an atomic mass of 24.312 and consists of three isotopes. The major isotope is 24Mg, natu- ral abundance 78.99%, relative atomic mass 23.98504. The next most abundant isotope is 26Mg, relative atomic mass 25.98259. The third most abundant isotope is 25Mg, whose natural abun- dance is in the ratio of 0.9083 to that of 26Mg. Find the relative atomic mass of 25Mg.