Change result -> outcome
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@ -18,9 +18,9 @@ each outcome is $1/6$.
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For example, we can calculate the following probabilities:
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\begin{itemize}[noitemsep]
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\item $P(\textrm{''the result is 4''})=1/6$
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\item $P(\textrm{''the result is not 6''})=5/6$
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\item $P(\textrm{''the result is even''})=1/2$
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\item $P(\textrm{''the outcome is 4''})=1/6$
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\item $P(\textrm{''the outcome is not 6''})=5/6$
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\item $P(\textrm{''the outcome is even''})=1/2$
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\end{itemize}
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\section{Calculation}
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@ -79,7 +79,7 @@ where $X$ contains all possible outcomes
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and $A$ is a subset of outcomes.
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For example, when drawing a dice, the outcomes are
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\[X = \{1,2,3,4,5,6\}.\]
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Now, for example, the event ''the result is even''
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Now, for example, the event ''the outcome is even''
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corresponds to the set
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\[A = \{2,4,6\}.\]
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@ -91,7 +91,7 @@ of probabilities of outcomes using the formula
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For example, when throwing a dice,
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$p(x)=1/6$ for each outcome $x$,
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so the probability of the event
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''the result is even'' is
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''the outcome is even'' is
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\[p(2)+p(4)+p(6)=1/2.\]
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The total probability of the outcomes in $X$ must
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@ -144,11 +144,11 @@ is calculated using the formula
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\[P(A \cup B)=P(A)+P(B)-P(A \cap B).\]
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For example, when throwing a dice,
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the union of the events
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\[A=\textrm{''the result is even''}\]
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\[A=\textrm{''the outcome is even''}\]
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and
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\[B=\textrm{''the result is less than 4''}\]
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\[B=\textrm{''the outcome is less than 4''}\]
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is
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\[A \cup B=\textrm{''the result is even or less than 4''},\]
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\[A \cup B=\textrm{''the outcome is even or less than 4''},\]
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and its probability is
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\[P(A \cup B) = P(A)+P(B)-P(A \cap B)=1/2+1/2-1/6=5/6.\]
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@ -174,8 +174,8 @@ Using the above sets,
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\[P(A | B)= 1/3,\]
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because the outcomes of $B$ are
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$\{1,2,3\}$, and one of them is even.
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This is the probability of an even result
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if we know that the result is between $1 \ldots 3$.
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This is the probability of an even outcome
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if we know that the outcome is between $1 \ldots 3$.
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\subsubsection{Intersection}
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@ -208,8 +208,8 @@ A \key{random variable} is a value that is generated
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by a random process.
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For example, when throwing two dice,
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a possible random variable is
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\[X=\textrm{''the sum of the results''}.\]
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For example, if the results are $[4,6]$
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\[X=\textrm{''the sum of the outcomes''}.\]
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For example, if the outcomes are $[4,6]$
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(meaning that we first throw a four and then a six),
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then the value of $X$ is 10.
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@ -232,7 +232,7 @@ The expected value can be calculated as the sum
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where $x$ goes through all possible values of $X$.
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For example, when throwing a dice,
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the expected result is
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the expected outcome is
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\[1/6 \cdot 1 + 1/6 \cdot 2 + 1/6 \cdot 3 + 1/6 \cdot 4 + 1/6 \cdot 5 + 1/6 \cdot 6 = 7/2.\]
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A useful property of expected values is \key{linearity}.
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