Question
Fred decides to take a series of n tests, to diagnose whether he has a certain disease (any individual test is not perfectly reliable, so
Fred decides to take a series of n tests, to diagnose whether he has a certain disease
(any individual test is not perfectly reliable, so he hopes to reduce his uncertainty by
taking multiple tests). Let D be the event that he has the disease, p = P(D) be the
prior probability that he has the disease, and q = 1
(a) There are two crimson jars (labeled C1 and C2) and two mauve jars (labeled M1 and
M2). Each jar contains a mixture of green gummi bears and red gummi bears. Show by
example that it is possible that C1 has a much higher percentage of green gummi bears
than M1, and C2 has a much higher percentage of green gummi bears than M2, yet if
the contents of C1 and C2 are merged into a new jar and likewise for M1 and M2, then
the combination of C1 and C2 has a lower percentage of green gummi bears than the
combination of M1 and M2.
(b) Explain how (a) relates to Simpson's paradox, both intuitively and by explicitly
defining events A, B, C as in the statement of Simpson's paradox.
52. As explained in this chapter, Simpson's paradox says that it is possible to have events
A, B, C such that P(A|B,C)
P(A|B) > P(A|Bc).
(a) Can Simpson's paradox occur if A and B are independent? If so, give a concrete
example (with both numbers and an interpretation); if not, prove that it is impossible.
(b) Can Simpson's paradox occur if A and C are independent? If so, give a concrete
example (with both numbers and an interpretation); if not, prove that it is impossible.
(c) Can Simpson's paradox occur if B and C are independent? If so, give a concrete
example (with both numbers and an interpretation); if not, prove that it is impossible.
Step by Step Solution
There are 3 Steps involved in it
Step: 1
Get Instant Access to Expert-Tailored Solutions
See step-by-step solutions with expert insights and AI powered tools for academic success
Step: 2
Step: 3
Ace Your Homework with AI
Get the answers you need in no time with our AI-driven, step-by-step assistance
Get Started