To find the volume of a similar ballon with radius 10.4 cm, we will simply take the proportion
Let v be the volume of the similar ballon;
[tex]\frac{74}{v}=\frac{2.6}{10.4}[/tex]Cross -multiply
[tex]2.6v\text{ = 769.6}[/tex]Divide both-side by 2.6
[tex]v=296\operatorname{cm}^3[/tex]