The length of the box is 3 x the height of 12 inches = <<3*12=36>>36 inches.

The width of the box is 36 inches / 4 = <<36/4=9>>9 inches.

The volume of the box is the height of 12 inches x the length of 36 inches x the width of 9 inches = <<12*36*9=3888>>3,888 cubic inches.

# Answer

3,888
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Justin has a box that is 12 inches in height. The length of the box is 3 times its height and 4 times its width. What is the volume of the box?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
3,888
Justin has a box that is 12 inches in height. The length of the box is 3 times its height and 4 times its width. What is the volume of the box?
train