$n_{NaOH pu}=\frac{34,1.1,1.10}{40.100.\frac{100+25}{100}}=n_{este}\Rightarrow M_{este}=\frac{6,6}{n_{este}}=88$$\Rightarrow M_{R_1COOR}=88\Rightarrow M_{R_1}+M_R=44\Rightarrow R_1-R:C_3H_8$
$\Rightarrow X:HCOOCH_2CH_2CH_3 ; HCOOCH(CH_3)_2 ; CH_3COOC_2H_5$
$CH_3CH_2COOCH_3$