办理业务所需的时间Y/分
1
2
3
4
5
频率
0.1
0.4
0.3
从第一个顾客开始办理业务时计时,据上表估计第三个顾客等待不超过4分钟就开始办理业务的概率为( )
I just heard____ bank where Dora works was robbed by____ gunman wearing a mask.