Without writing down any calculations, determine the mean of the distribution shown. The variance of this probability distribution is (you can do this in your head!) $$\begin{array} { | l | c | c | c | }
\hline \mathrm { x } & - 1 & 0 & 1 \
\hline \mathrm { P } ( \mathrm { x } ) & 0.25 & 0.50 & 0.25 \
\hline
\end{array}$$
A) 0.25
B) 0.50
C) 0.75
D) 1.00

Question

Without writing down any calculations, determine the mean of the distribution shown. The variance of this probability distribution is (you can do this in your head!) $$\begin{array} { | l | c | c | c | } 
\hline \mathrm { x } & - 1 & 0 & 1 \
\hline \mathrm { P } ( \mathrm { x } ) & 0.25 & 0.50 & 0.25 \
\hline
\end{array}$$
A) 0.25
B) 0.50
C) 0.75
D) 1.00

Quizplus · Accepted Answer

The mean of a probability distribution is the expected value, which is the sum of each possible value multiplied by its probability. In this case, the mean is (-1)(0.25) + (0)(0.50) + (1)(0.25) = 0.

Without Writing Down Any Calculations, Determine the Mean of the Distribution