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Construct finite independent sums and compare repeated copies with scaling

DIFFICULTYchallenge
Question 1 of 8

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A finite random variable X has the following distribution. The variables X₁,...,Xₙ are mutually independent and each has exactly this distribution

\(x\)\(\Pr(X=x)\)
\(-3\)\(\frac{2}{9}\)
\(-1\)\(\frac{4}{9}\)
\(1\)\(\frac{1}{3}\)
\[n=5,\qquad S_n=X_1+\cdots+X_n\]

Also define \(T=5X\) using just one draw of X, multiplied by 5. T reuses that same value; it is not a sum of independent draws

4 marks

Complete both means and both variances. Give exact values