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Practice exercise for GED Can I find the correct forms doing mean variance and standard deviation discrete probability

Practice exercise for GED Can I find the correct forms doing mean variance and standard-example-1
User Arrowsome
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1 Answer

19 votes
19 votes

Given

Probability distribution table

Find

Mean , variance and Standard Deviation

Step-by-step explanation

As we have given

X = 0 , 1 , 2 , 3 , 4 , 5

P(X) = 0.15 , 0.20 , 0.35 , 0.22 , 0.07 , 0.01

Mean

Formula is given by


\mu=\sum_^X\cdot P(X)

first we find the values of X.P(X)


\begin{gathered} \sum_^X\cdot P(X)=0+0.20+0.70+0.66+0.28+0.05 \\ \sum_^X\cdot P(X)=1.89 \end{gathered}

Variance =


\begin{gathered} \sum_^(x-\mu)^2P(x) \\ 0.54+0.16+0+0.27+0.31+0.10 \\ 1.3779\approx1.38 \end{gathered}

standard deviation =


\begin{gathered} √(variance) \\ √(1.38) \\ 1.174\approx1.17 \end{gathered}

Final Answer

Therefore ,

Mean = 1.89

Variance = 1.38

Standard Deviation = 1.17

User Jett
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