б) $$\alpha : 13\frac{1}{4} = 1\frac{3}{4}$$
$$\alpha : \frac{53}{4} = \frac{7}{4}$$
$$\alpha = \frac{7}{4} \cdot \frac{53}{4}$$
$$\alpha = \frac{7 \cdot 53}{4 \cdot 4}$$
$$\alpha = \frac{371}{16}$$
$$\alpha = 23\frac{3}{16}$$
Ответ: $$\alpha = 23\frac{3}{16}$$