exercise:9216b4c64a: Difference between revisions

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(Created page with "<div class="d-none"><math> \newcommand{\NA}{{\rm NA}} \newcommand{\mat}[1]{{\bf#1}} \newcommand{\exref}[1]{\ref{##1}} \newcommand{\secstoprocess}{\all} \newcommand{\NA}{{\rm NA}} \newcommand{\mathds}{\mathbb}</math></div> A doctor assumes that a patient has one of three diseases <math>d_1</math>, <math>d_2</math>, or <math>d_3</math>. Before any test, he assumes an equal probability for each disease. He carries out a test that will be positive with probability .8...")
 
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<div class="d-none"><math>
A doctor assumes that a patient has one of three diseases <math>d_1</math>, <math>d_2</math>, or <math>d_3</math>.  Before any test, he assumes an equal probability for each disease.  
\newcommand{\NA}{{\rm NA}}
\newcommand{\mat}[1]{{\bf#1}}
\newcommand{\exref}[1]{\ref{##1}}
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\newcommand{\NA}{{\rm NA}}
\newcommand{\mathds}{\mathbb}</math></div> A doctor assumes that a patient has one of three diseases <math>d_1</math>, <math>d_2</math>,
or <math>d_3</math>.  Before any test, he assumes an equal probability for each disease.  
He carries out a test that will be positive with probability .8 if the patient
He carries out a test that will be positive with probability .8 if the patient
has <math>d_1</math>, .6 if he has disease <math>d_2</math>, and .4 if he has disease <math>d_3</math>.  Given that
has <math>d_1</math>, .6 if he has disease <math>d_2</math>, and .4 if he has disease <math>d_3</math>.  Given that
the outcome of the test was positive, what probabilities should the doctor now
the outcome of the test was positive, what probabilities should the doctor now
assign to the three possible diseases?
assign to the three possible diseases?

Latest revision as of 00:45, 13 June 2024

A doctor assumes that a patient has one of three diseases [math]d_1[/math], [math]d_2[/math], or [math]d_3[/math]. Before any test, he assumes an equal probability for each disease. He carries out a test that will be positive with probability .8 if the patient has [math]d_1[/math], .6 if he has disease [math]d_2[/math], and .4 if he has disease [math]d_3[/math]. Given that the outcome of the test was positive, what probabilities should the doctor now assign to the three possible diseases?