if the total frequency 

is 685 and median is 42.6 then missing frequencies are

Given $180+f_1+34+180+136+f_2+50=685,f_1+f_2=105\cdots \left(1\right)$

Median class $N=\sum f_i=685$

$\frac{N}{2}=\frac{685}{2}=342.5<394+f_1$  Median $=40-50,f=180,c.f=214+f_1$

$\therefore$Median $=L+\left(\frac{\frac{N}{2}-c.f}{f}\right)\times c$

$\Rightarrow 42.6=40+\frac{128.5-f_1}{18}$