Find the expected value of the random variable with the given probability distribution.

Do not round your answer.

[tex]\[
\mu = ?
\][/tex]

\begin{tabular}{r|c}
[tex]$x$[/tex] & [tex]$P$[/tex] \\
\hline
-1 & 0.05 \\
1 & 0.18 \\
3 & 0.21 \\
5 & 0.23 \\
7 & 0.14 \\
9 & 0.19 \\
\end{tabular}



Answer :

To find the expected value [tex]\(\mu\)[/tex] of a random variable with a given probability distribution, we use the formula for the expected value of a discrete random variable:

[tex]\[ \mu = \sum_{i} x_i \cdot P(x_i) \][/tex]

This means we multiply each possible value [tex]\(x_i\)[/tex] of the random variable by the corresponding probability [tex]\(P(x_i)\)[/tex] and then sum up all these products. Let's do this step by step with the given values.

Given:
[tex]\[ \begin{array}{r|c} x & P(x) \\ \hline -1 & 0.05 \\ 1 & 0.18 \\ 3 & 0.21 \\ 5 & 0.23 \\ 7 & 0.14 \\ 9 & 0.19 \\ \end{array} \][/tex]

1. Multiply each [tex]\(x\)[/tex] value by its corresponding probability:
- For [tex]\(x = -1\)[/tex]: [tex]\(-1 \cdot 0.05 = -0.05\)[/tex]
- For [tex]\(x = 1\)[/tex]: [tex]\(1 \cdot 0.18 = 0.18\)[/tex]
- For [tex]\(x = 3\)[/tex]: [tex]\(3 \cdot 0.21 = 0.63\)[/tex]
- For [tex]\(x = 5\)[/tex]: [tex]\(5 \cdot 0.23 = 1.15\)[/tex]
- For [tex]\(x = 7\)[/tex]: [tex]\(7 \cdot 0.14 = 0.98\)[/tex]
- For [tex]\(x = 9\)[/tex]: [tex]\(9 \cdot 0.19 = 1.71\)[/tex]

2. Sum up all these products:
[tex]\[ -0.05 + 0.18 + 0.63 + 1.15 + 0.98 + 1.71 \][/tex]

3. Perform the addition:
[tex]\[ -0.05 + 0.18 = 0.13 \][/tex]
[tex]\[ 0.13 + 0.63 = 0.76 \][/tex]
[tex]\[ 0.76 + 1.15 = 1.91 \][/tex]
[tex]\[ 1.91 + 0.98 = 2.89 \][/tex]
[tex]\[ 2.89 + 1.71 = 4.60 \][/tex]

Thus, the expected value [tex]\(\mu\)[/tex] of the random variable is:

[tex]\[ \mu = 4.6000000000000005 \][/tex]

Hence, the expected value of the given random variable is:

[tex]\(\mu = 4.6000000000000005\)[/tex].

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