1 2 1 б) 4 : 2 = 3 : t;

б) $$4\frac{1}{2} : 2\frac{2}{5} = 3\frac{1}{4} : t$$

$$\frac{9}{2} : \frac{12}{5} = \frac{13}{4} : t$$

$$t = \frac{\frac{12}{5} \cdot \frac{13}{4}}{\frac{9}{2}} = \frac{\frac{3 \cdot 13}{5}}{\frac{9}{2}} = \frac{39 \cdot 2}{5 \cdot 9} = \frac{13 \cdot 2}{5 \cdot 3} = \frac{26}{15} = 1\frac{11}{15}$$

Ответ: $$t = 1\frac{11}{15}$$