If the ratio of girls to boys in a class is 5.5:4.5, what is the percentage of girls in the class?
某班女生与男生之比为5.5：4.5，那么女生占全班的百分比为多少．
<gadget id="calculator">5.5 + 4.5</gadget>
<output>10</output>

<gadget id="calculator">5.5 / 10</gadget>
<output>0.55</output>

<result>0.55</result>