Solve the equation: 4: 3.25 = x: (1/2).
解方程：4：3.25=x：(1/2)．
<gadget id="calculator">4 / 3.25</gadget>
<output>1.230769</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1.230769 * (1/2)</gadget>
<output>0.615385</output>

<result>0.615385</result>