Chuchu participated in the excursion activities of the summer camp. The original plan was to walk 3.8 kilometers per hour and reach the destination in 3 hours. Actually finished the scheduled journey half an hour ahead of schedule. How many kilometers does Chuchu actually walk per hour?
楚楚参加了夏令营的远足活动原计划每小时走3.8千米，3小时到达目的地．实际提前半小时走完原定路程．楚楚实际每小时走多少千米？
<gadget id="calculator">3 - 0.5</gadget>
<output>2.5</output>

<gadget id="calculator">3 / 2.5</gadget>
<output>1.2</output>

<gadget id="calculator">3.8 * 1.2</gadget>
<output>4.56</output>

<result>4.56</result>