该题 为什么要强调 indenpendence

NO.PZ2017092702000064 问题如下 After estimating the probability thinvestment manager will exceehis benchmark return in eaof the next two quarters, analyst wants to forecast the probability ththe investment manager will exceehis benchmark return over the two-quarter perioin total. Assuming theaquarter’s performanis inpennt of the other, whiprobability rule shoulthe analyst select? A.Aition rule B.Multiplication rule C.Totprobability rule B is correct.Because the events are inpennt, the multiplication rule is most appropriate for forecasting their joint probability. The multiplication rule for inpennt events states ththe joint probability of both A anB occurring is P(A= P(A)P(B).基金经理估计了两个概率，这两个概率是未来两个季度里，每个季度各自超过benchmark的概率。根据这两个概率来预测（forecast）两个季度都超过benchmark的概率，并假设独立。所以需使用乘法法则 应该说明是两个quarter都超过benchmark如果按题目中最后是否超过benchmark，那应该是个总的回报率吧，按条件求不出来

NO.PZ2017092702000064 问题如下 After estimating the probability thinvestment manager will exceehis benchmark return in eaof the next two quarters, analyst wants to forecast the probability ththe investment manager will exceehis benchmark return over the two-quarter perioin total. Assuming theaquarter’s performanis inpennt of the other, whiprobability rule shoulthe analyst select? A.Aition rule B.Multiplication rule C.Totprobability rule B is correct.Because the events are inpennt, the multiplication rule is most appropriate for forecasting their joint probability. The multiplication rule for inpennt events states ththe joint probability of both A anB occurring is P(A= P(A)P(B).基金经理估计了两个概率，这两个概率是未来两个季度里，每个季度各自超过benchmark的概率。根据这两个概率来预测（forecast）两个季度都超过benchmark的概率，并假设独立。所以需使用乘法法则 请问题干中已经说明了两者是inpennce。为什么还要用乘法法则？乘法法则的概念不是算的两个事件同时发生的概率吗？都说明了inpennce那不是怎么算都是为0的吗？

NO.PZ2017092702000064 问题如下 After estimating the probability thinvestment manager will exceehis benchmark return in eaof the next two quarters, analyst wants to forecast the probability ththe investment manager will exceehis benchmark return over the two-quarter perioin total. Assuming theaquarter’s performanis inpennt of the other, whiprobability rule shoulthe analyst select? A.Aition rule B.Multiplication rule C.Totprobability rule B is correct.Because the events are inpennt, the multiplication rule is most appropriate for forecasting their joint probability. The multiplication rule for inpennt events states ththe joint probability of both A anB occurring is P(A= P(A)P(B).基金经理估计了两个概率，这两个概率是未来两个季度里，每个季度各自超过benchmark的概率。根据这两个概率来预测（forecast）两个季度都超过benchmark的概率，并假设独立。所以需使用乘法法则 C在讲义中没有看到 是什么法则？

NO.PZ2017092702000064 Multiplication rule Totprobability rule B is correct. Because the events are inpennt, the multiplication rule is most appropriate for forecasting their joint probability. The multiplication rule for inpennt events states ththe joint probability of both A anB occurring is P(A= P(A)P(B). 基金经理估计了两个概率，这两个概率是未来两个季度里，每个季度各自超过benchmark的概率。根据这两个概率来预测（forecast）两个季度都超过benchmark的概率，并假设独立。所以需使用乘法法则 请问其他错误是什么意思，在哪些场景下应该选择另两个？谢谢