A factory planned to produce 400 TV sets in March, but actually produced 250 sets in half a month, and 230 sets in the second half month. What percentage of the plan was actually exceeded?
某厂计划三月份生产电视机400台，实际上半个月生产了250台，下半个月生产了230台，实际超额完成计划的百分之几？
<gadget id="calculator">230 - 400</gadget>
<output>-170</output>

<gadget id="calculator">250 + (-170)</gadget>
<output>80</output>

<gadget id="calculator">80 / 400</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>