Retries
The following table contains the probability distribution for X = the number of retries necessary to successfully transmit a 1024K data package through a double satellite media.
$\begin{array} { | c | c c c c | } \hline \boldsymbol { x } & 0 & 1 & 2 & 3 \\\hline \boldsymbol { p } ( \boldsymbol { x } ) & 0.35 & 0.35 & 0.25 & 0.05 \\\hline\end{array}$
-If X and Y are independent variables with V(X)= 23.48 and V(Y)= 36.52,then the standard deviation of W = X + Y is $\sigma$ _w = 7.746.

Question

Retries
The following table contains the probability distribution for X = the number of retries necessary to successfully transmit a 1024K data package through a double satellite media.

\begin{array} { | c | c c c c | } \hline \boldsymbol { x } & 0 & 1 & 2 & 3 \\\hline \boldsymbol { p } ( \boldsymbol { x } ) & 0.35 & 0.35 & 0.25 & 0.05 \\\hline\end{array}

-If X and Y are independent variables with V(X)= 23.48 and V(Y)= 36.52,then the standard deviation of W = X + Y is

\sigma

_w = 7.746.

Quizplus · Accepted Answer

The formula for the variance of the sum of independent random variables is:

V(W) = V(X) + V(Y)

Substituting the given values:

V(W) = 23.48 + 36.52

V(W) = 60

Taking the square root of the variance, we get:

σW = √(60)

σW = 7.746

Therefore, the statement is true and the answer is A.

Retries the Following Table Contains the Probability Distribution for X

Retries
the Following Table Contains the Probability Distribution for X