In a single throw of a die, if X denotes the number on its upper face, then the mean of X is,
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → \( \displaystyle\frac{7}{2} \)
X takes the values 1, 2, 3, 4, 5, 6, each with probability \( \frac{1}{6} \). The mean is
\( \displaystyle E(X)=\sum x\,P(X=x) \)
\( \displaystyle =\frac{1+2+3+4+5+6}{6} \)
\( \displaystyle =\frac{21}{6}=\frac{7}{2} \)