Variance of a sum drawn without replacement

MediumRandom Variables~5m

From a bag of ten tickets numbered $1$ through $10$ , you draw 3 tickets without replacement and add their numbers. What is the variance of that sum? Give a decimal to four places.

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Draws without replacement are dependent - include the covariance.
$\operatorname{Var}(\text{sum})=n\sigma^2\frac{N-n}{N-1}$ with $\sigma^2=(10^2-1)/12$ .

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19.25 (± 0.01)

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Variance of a sum drawn without replacement

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