$(16 : 1\frac{1}{3} - 4\frac{5}{9} + 2\frac{3}{4} : 11 + 3\frac{1}{4}) : ((7\frac{1}{3} - 6\frac{5}{9}) * \frac{5}{28}) = (\frac{16}{1} * \frac{3}{4} - \frac{41}{9} + \frac{11}{4} * \frac{1}{11} + \frac{13}{4}) : ((1\frac{1}{3} - \frac{5}{9}) * \frac{5}{28}) = (\frac{12}{1} - \frac{41}{9} + \frac{1}{4} + \frac{13}{4}) : ((\frac{12}{9} - \frac{5}{9}) * \frac{5}{28}) = (\frac{12 * 36 - 41 * 4 + 1 * 9 + 13 * 9}{36}) : (\frac{7}{9} * \frac{5}{7 * 4}) = \frac{394}{36} : \frac{5}{36} = \frac{394}{36} * \frac{36}{5} = \frac{394}{5} = 78\frac{4}{5}$