NO.PZ2023091601000010
问题如下：
An
analyst is examining a portfolio that consists of 600 subprime mortgages and
400 prime mortgages. Of the subprime mortgages, 120 are late on their payments.
Of the prime mortgages, 40 are late on their payments. If the analyst randomly
selects a mortgage from the portfolio and it is currently late on its payments,
what is the probability that it is a subprime mortgage?
选项：
A.
60%
B.
67%
C.
75%
D.
80%
解释：
In order to solve
this conditional probability question, first calculate the probability that any
one mortgage in the portfolio is late. This is: P(Mortgage is late) = (120 +
40)/1000 = 16%.
Next use the
conditional probability relationship as follows:
P (Mortgage
subprime | Mortgage is late) = P(Mortgage subprime and late) / P(Mortgage is
late)
Since P(Mortgage
subprime and late) = 120/1000 = 12%;
Therefore P(Mortgage
subprime | Mortgage is late) = 12% / 16% = 0.75 = 75%.
Hence the probability
that a random late mortgage selected from this portfolio turns out to be
subprime is 75%.
贝叶斯画图法怎么计算。
