12 darts are thrown at a dartboard. The probability of hitting a bull's-eye is 0.1. Let X be the number of bull's-eyes hit. Calculate the expected value of the given random variable X.
A) $E ( X ) = 0.6$
B) $E ( X ) = 1$
C) $E ( X ) = 1.2$
D) $E ( X ) = 6$
E) $E ( X ) = 2$

Question

12 darts are thrown at a dartboard. The probability of hitting a bull's-eye is 0.1. Let X be the number of bull's-eyes hit. Calculate the expected value of the given random variable X.  
A)  $E ( X ) = 0.6$
B) $E ( X ) = 1$
C) $E ( X ) = 1.2$
D) $E ( X ) = 6$
E) $E ( X ) = 2$

Quizplus · Accepted Answer

The expected value $E(X)$ for a binomial distribution is calculated as $n \times p$, where $n$ is the number of trials (12 darts) and $p$ is the probability of success (0.1). Thus, $E(X) = 12 \times 0.1 = 1.2$.

12 Darts Are Thrown at a Dartboard E(X)=0.6E ( X ) = 0.6E(X)=0.6

12 Darts Are Thrown at a Dartboard $E ( X ) = 0.6$