Xiaoyue and Archie lowered the military flag in a competition. The two are of equal level. The two agree to match 7 rounds, and the first to win 4 rounds wins. There have been 3 rounds of competition, Xiaoyue has won 2 rounds, and Archie has won 1 round. May I ask: What is the probability that Xiaoyue will win in the end?
小悦与阿奇比赛下军旗，两人水平相当，两人约定赛7局，先赢4局者胜．现在已经比了3局，小悦胜了2局，阿奇胜了1局．请问：小悦获得最后胜利的概率有多少？
<gadget id="calculator">4 - 2</gadget>
<output>2</output>

<gadget id="calculator">7 - 3</gadget>
<output>4</output>

<gadget id="calculator">2 / 4</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>