Compute the mean of the random variable with the given discrete probability distribution.
$\begin{array} { c c }
\hline x & P ( x ) \
\hline 0 & 0.2 \
15 & 0.05 \
25 & 0.45 \
30 & 0.3 \
\hline
\end{array}$
A) 11.0
B) 121.5
C) 21
D) 17.5

Question

Compute the mean of the random variable with the given discrete probability distribution. 
$\begin{array} { c c } 
\hline x & P ( x ) \
\hline 0 & 0.2 \
15 & 0.05 \
25 & 0.45 \
30 & 0.3 \
\hline
\end{array}$
A) 11.0
B) 121.5
C) 21
D) 17.5

Quizplus · Accepted Answer

To find the mean of a discrete probability distribution, we multiply each possible value of the random variable by its corresponding probability, and then add up all of these products. That is:

mean = (0)(0.2) + (15)(0.05) + (25)(0.45) + (30)(0.3) = 21

Therefore, the best choice is C, with a mean of 21.

Compute the Mean of the Random Variable with the Given xP(x)00.2150.05250.45300.3\begin{array} { c c } \hline x & P ( x ) \\\hline 0 & 0.2 \\15 & 0.05 \\25 & 0.45 \\30 & 0.3 \\\hline\end{array}x0152530​P(x)0.20.050.450.3​​

Compute the Mean of the Random Variable with the Given $\begin{array} { c c } \hline x & P ( x ) \\\hline 0 & 0.2 \\15 & 0.05 \\25 & 0.45 \\30 & 0.3 \\\hline\end{array}$