Given ((x)/15)=((1.8)/(7.5)), find the unknown x.
已知((x)/15)=((1.8)/(7.5))，求未知数x．
<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(1/15) * 7.5</gadget>
<output>0.5</output>

<gadget id="calculator">1.8 / 0.5</gadget>
<output>3.6</output>

<result>3.6</result>