The students have to select 4 candidates from 9 candidates to participate in the speech contest. What is the probability of each candidate being selected?
同学们要在9名候选人当中选出4名参加演讲比赛，每位候选人被选中的可能性为多少．
<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<result>4/9 = around 0.444444</result>