H) Решим пропорцию:
$$3.8 : c = 2 : 2\frac{2}{19}$$
$$3.8 : c = 2 : \frac{40}{19}$$
$$c = \frac{3.8 \cdot \frac{40}{19}}{2} = \frac{3.8 \cdot 40}{19 \cdot 2} = \frac{152}{38} = 4$$
Ответ: $$c = 4$$