$ \frac{5}{12}+ \frac{3}{4}+\frac{5}{6}+\frac{1}{2} =\frac{5+9+10+6}{12}=\frac{30}{12}$ $\frac{30}{12}\div 4=\frac{30}{12}\times \frac{1}{4}=\frac{5}{8}$