The students of Jingyuan No. 1 Middle School had marching training. They originally planned to walk 11.25 kilometers in 3 hours, but they actually walked 4.5 kilometers per hour. How many kilometers per hour did you actually walk more than the original plan?
泾源一中学生进行行军训练，原计划3小时走完11.25千米，实际每小时走了4.5千米．实际比原计划平均每小时多走多少千米？
<gadget id="calculator">11.25 / 3</gadget>
<output>3.75</output>

<gadget id="calculator">4.5 - 3.75</gadget>
<output>0.75</output>

<result>0.75</result>