v****e
发帖数: 19471 | 1 随口出一个吧，出错了的话大家指正哈。
Known: on a random day:
1. Probability that Index A rises is 60%
2. If Index A rises, the probability that Index B also rises is 80%
3. If Index A doesn't rise, there is STILL a 15% probability that Index B
rises.
Question: if Index B rises, what is the probability that Index A does NOT
rise? |
b********t
发帖数: 8181 | |
s*****n
发帖数: 5488 | 3 just buy index B
【在 v****e 的大作中提到】
: 随口出一个吧，出错了的话大家指正哈。
: Known: on a random day:
: 1. Probability that Index A rises is 60%
: 2. If Index A rises, the probability that Index B also rises is 80%
: 3. If Index A doesn't rise, there is STILL a 15% probability that Index B
: rises.
: Question: if Index B rises, what is the probability that Index A does NOT
: rise?
|
c****e
发帖数: 9482 | |
g*****u
发帖数: 14294 | 5 俺们古板的女ID打扮打扮还蛮turn on的。
形势喜人。
【在 c****e 的大作中提到】
: 大学概率的基本题
: 1/9
|
w*******t
发帖数: 2459 | 6 if B(up) --> buy A(up) for sure...
the chance (otherwise) is pretty low... |
G*******m
发帖数: 16326 | 7 AR AN
BR 48 6 54
BN 12 34 46 |
G*******m
发帖数: 16326 | |
v****e
发帖数: 19471 | 9 美女冰雪，请把玉照和电话发到我信箱。谢谢。
【在 c****e 的大作中提到】
: 大学概率的基本题
: 1/9
|
w*******t
发帖数: 2459 | 10 这个靠谱...上头那个就...
【在 G*******m 的大作中提到】
: 6%
|
|
|
w*******t
发帖数: 2459 | 11 受不了了
【在 v****e 的大作中提到】
: 美女冰雪，请把玉照和电话发到我信箱。谢谢。
|
v****e
发帖数: 19471 | 12 思维正确，答案错误。
【在 G*******m 的大作中提到】
: 6%
|
f******o
发帖数: 4689 | 13 不会呀，就记得用全概率公式好像。老了。
【在 v****e 的大作中提到】
: 随口出一个吧，出错了的话大家指正哈。
: Known: on a random day:
: 1. Probability that Index A rises is 60%
: 2. If Index A rises, the probability that Index B also rises is 80%
: 3. If Index A doesn't rise, there is STILL a 15% probability that Index B
: rises.
: Question: if Index B rises, what is the probability that Index A does NOT
: rise?
|
G*******m
发帖数: 16326 | 14 P(BR) = 0.54
P(BR/AN) = 0.06
P = P(BR/AN) / P(BR) = 0.06/0.54 = 1/9
AR AN
BR 48 6 54
BN 12 34 46 |
v****e
发帖数: 19471 | 15 yep. good job.
【在 G*******m 的大作中提到】
: P(BR) = 0.54
: P(BR/AN) = 0.06
: P = P(BR/AN) / P(BR) = 0.06/0.54 = 1/9
: AR AN
: BR 48 6 54
: BN 12 34 46
|
u****d
发帖数: 23938 | 16 Bayes conditional probability using A as a partition |
c****2
发帖数: 1076 | 17 Bayes probability, undergraduate 2nd grade |
G*******m
发帖数: 16326 | |
G*******m
发帖数: 16326 | |
G*******m
发帖数: 16326 | |
