首页 | 学习中心 | 注册 登录
返回列表 发帖
bmaggie

UID
137541 
帖子
3658 
主题
530 
注册时间
2009-7-1 
最后登录
2012-2-18 
1# 跳转到 » 倒序看帖
打印
tT
发表于 2010-4-12 14:20 | 只看该作者

Reading 8: Probability Concepts-LOS g习题精选

div, class, following, between, border
Session 2: Quantitative Methods: Basic Concepts
Reading 8: Probability Concepts

LOS g: Distinguish between dependent and independent events

 

 

 

If X and Y are independent events, which of the following is most accurate?

A)
 P(X or Y) = (P(X)) × (P(Y)).
B)
 P(X | Y) = P(X).
C)
 P(X or Y) = P(X) + P(Y).

收藏 分享

bmaggie

UID
137541 
帖子
3658 
主题
530 
注册时间
2009-7-1 
最后登录
2012-2-18 
2#
发表于 2010-4-12 14:21 | 只看该作者

If X and Y are independent events, which of the following is most accurate?

A)
 P(X or Y) = (P(X)) × (P(Y)).
B)
 P(X | Y) = P(X).
C)
 P(X or Y) = P(X) + P(Y).


Note that events being independent means that they have no influence on each other. It does not necessarily mean that they are mutually exclusive. Accordingly, P(X or Y) = P(X) + P(Y) ? P(X and Y). By the definition of independent events, P(X|Y) = P(X).

TOP

bmaggie

UID
137541 
帖子
3658 
主题
530 
注册时间
2009-7-1 
最后登录
2012-2-18 
3#
发表于 2010-4-12 14:45 | 只看该作者

A company says that whether it increases its dividends depends on whether its earnings increase. From this we know:

A)
 P(earnings increase | dividend increase) is not equal to P(earnings increase).
B)
 P(both dividend increase and earnings increase) = P(dividend increase).
C)
 P(dividend increase | earnings increase) is not equal to P(earnings increase).

TOP

bmaggie

UID
137541 
帖子
3658 
主题
530 
注册时间
2009-7-1 
最后登录
2012-2-18 
4#
发表于 2010-4-12 14:45 | 只看该作者

A company says that whether it increases its dividends depends on whether its earnings increase. From this we know:

A)
 P(earnings increase | dividend increase) is not equal to P(earnings increase).
B)
 P(both dividend increase and earnings increase) = P(dividend increase).
C)
 P(dividend increase | earnings increase) is not equal to P(earnings increase).


If two events A and B are dependent, then the conditional probabilities of P(A | B) and P(B | A) will not equal their respective unconditional probabilities (of P(A) and P(B), respectively). Both remaining choices may or may not occur, e.g., P(A | B) = P(B) is possible but not necessary.

TOP

bmaggie

UID
137541 
帖子
3658 
主题
530 
注册时间
2009-7-1 
最后登录
2012-2-18 
5#
发表于 2010-4-12 14:45 | 只看该作者

If the outcome of event A is not affected by event B, then events A and B are said to be:

A)
 statistically independent.
B)
 conditionally dependent.
C)
 mutually exclusive.

TOP

bmaggie

UID
137541 
帖子
3658 
主题
530 
注册时间
2009-7-1 
最后登录
2012-2-18 
6#
发表于 2010-4-12 14:46 | 只看该作者

If the outcome of event A is not affected by event B, then events A and B are said to be:

A)
 statistically independent.
B)
 conditionally dependent.
C)
 mutually exclusive.


If the outcome of one event does not influence the outcome of another, then the events are independent.

TOP

zaestau

Rank: 2

UID
72515 
帖子
873 
主题
0 
注册时间
2007-9-24 
最后登录
2020-5-12 
7#
发表于 2010-4-26 23:31 | 只看该作者
c

TOP

返回列表