Weixing Real Estate has built an 18-story residential building, each floor is 4 meters high, and the foundation is 9 meters deep. According to this ratio, Weixing Real Estate plans to rebuild a 24-story residential building. How deep is the foundation? (Answer with proportional knowledge)
伟星置业造了一座18层的住宅楼，每层高4米，地基深为9米．按照这个比例伟星置业准备再造一座24层的住宅楼，需打多深的地基？(用比例知识解答)
<gadget id="calculator">4 * 24</gadget>
<output>96</output>

<gadget id="calculator">18 / 9</gadget>
<output>2</output>

<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">96 / 8</gadget>
<output>12</output>

<result>12</result>