The circumference of the bottom of the cylindrical bucket is 12.56 decimeters and the height is 6 decimeters. After filling a bucket of water, pour the water into a cuboid tank, which is still 21.5% empty. It is known that the width of a cuboid water tank is 4 decimeters, and the length is 1.5 times the width. Find the height of the water tank.
圆柱形水桶的底面周长12.56分米，高6分米．盛满一桶水后，把水倒入一个长方体水缸中，水缸还空着21.5%．已知长方体水缸宽4分米，长是宽的1.5倍，求水缸的高．
<gadget id="calculator">12.56 / 3.14 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">4 * 3.14 * 6</gadget>
<output>75.36</output>

<gadget id="calculator">21.5 / 100</gadget>
<output>0.215</output>

<gadget id="calculator">1 - 0.215</gadget>
<output>0.785</output>

<gadget id="calculator">75.36 / 0.785</gadget>
<output>96</output>

<gadget id="calculator">4 * 1.5</gadget>
<output>6</output>

<gadget id="calculator">96 / 4 / 6</gadget>
<output>4</output>

<result>4</result>