If she wants to make a box that is twice f the size of the original, we have to multiply each dimension by 2
[tex]\begin{gathered} 15\times2=30 \\ 4\times2=8 \\ 6\times2=12 \end{gathered}[/tex]Then, we multiply the new dimensions to find the volume of the new box
[tex]V=30\times8\times12=2,880in^3[/tex]