A coin is tossed twice and outcomes are recorded. If the random variable X represents the number of heads in the experiment, then the expectation of X will be:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 1
Possible values of $X$: $0,1,2$.
Probabilities:
$P(X=0)=\frac{1}{4}$, $P(X=1)=\frac{2}{4}$, $P(X=2)=\frac{1}{4}$
Expectation:
$E(X)=0\cdot\frac{1}{4}+1\cdot\frac{2}{4}+2\cdot\frac{1}{4}$
$=\frac{0+2+2}{4}=1$
final answer: $1$