问题
单项选择题
An analyst does research about joint probability and gathers the following information about a stock's dividend:
| Event 1 | Probability of a dividend change | 0.8 |
| Event 2 | Probability of a dividend increase | 0.5 |
A. 0.40
B. 0.50
C. 0.80
答案
参考答案：B
解析：
因为事件2股利上升已经包含在事件1股利变化之内，所以两者同时发生的联合概率就是股利上升的概率。