From 1f7ac8efba60ac2bad0fd54651075c2126a1b1e1 Mon Sep 17 00:00:00 2001 From: Antti H S Laaksonen Date: Fri, 21 Apr 2017 09:30:15 +0300 Subject: [PATCH] Change result -> outcome --- chapter24.tex | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) diff --git a/chapter24.tex b/chapter24.tex index a739613..6b9c762 100644 --- a/chapter24.tex +++ b/chapter24.tex @@ -18,9 +18,9 @@ each outcome is $1/6$. For example, we can calculate the following probabilities: \begin{itemize}[noitemsep] -\item $P(\textrm{''the result is 4''})=1/6$ -\item $P(\textrm{''the result is not 6''})=5/6$ -\item $P(\textrm{''the result is even''})=1/2$ +\item $P(\textrm{''the outcome is 4''})=1/6$ +\item $P(\textrm{''the outcome is not 6''})=5/6$ +\item $P(\textrm{''the outcome is even''})=1/2$ \end{itemize} \section{Calculation} @@ -79,7 +79,7 @@ where $X$ contains all possible outcomes and $A$ is a subset of outcomes. For example, when drawing a dice, the outcomes are \[X = \{1,2,3,4,5,6\}.\] -Now, for example, the event ''the result is even'' +Now, for example, the event ''the outcome is even'' corresponds to the set \[A = \{2,4,6\}.\] @@ -91,7 +91,7 @@ of probabilities of outcomes using the formula For example, when throwing a dice, $p(x)=1/6$ for each outcome $x$, so the probability of the event -''the result is even'' is +''the outcome is even'' is \[p(2)+p(4)+p(6)=1/2.\] The total probability of the outcomes in $X$ must @@ -144,11 +144,11 @@ is calculated using the formula \[P(A \cup B)=P(A)+P(B)-P(A \cap B).\] For example, when throwing a dice, the union of the events -\[A=\textrm{''the result is even''}\] +\[A=\textrm{''the outcome is even''}\] and -\[B=\textrm{''the result is less than 4''}\] +\[B=\textrm{''the outcome is less than 4''}\] is -\[A \cup B=\textrm{''the result is even or less than 4''},\] +\[A \cup B=\textrm{''the outcome is even or less than 4''},\] and its probability is \[P(A \cup B) = P(A)+P(B)-P(A \cap B)=1/2+1/2-1/6=5/6.\] @@ -174,8 +174,8 @@ Using the above sets, \[P(A | B)= 1/3,\] because the outcomes of $B$ are $\{1,2,3\}$, and one of them is even. -This is the probability of an even result -if we know that the result is between $1 \ldots 3$. +This is the probability of an even outcome +if we know that the outcome is between $1 \ldots 3$. \subsubsection{Intersection} @@ -208,8 +208,8 @@ A \key{random variable} is a value that is generated by a random process. For example, when throwing two dice, a possible random variable is -\[X=\textrm{''the sum of the results''}.\] -For example, if the results are $[4,6]$ +\[X=\textrm{''the sum of the outcomes''}.\] +For example, if the outcomes are $[4,6]$ (meaning that we first throw a four and then a six), then the value of $X$ is 10. @@ -232,7 +232,7 @@ The expected value can be calculated as the sum where $x$ goes through all possible values of $X$. For example, when throwing a dice, -the expected result is +the expected outcome is \[1/6 \cdot 1 + 1/6 \cdot 2 + 1/6 \cdot 3 + 1/6 \cdot 4 + 1/6 \cdot 5 + 1/6 \cdot 6 = 7/2.\] A useful property of expected values is \key{linearity}.