Find the standard deviation of the binomial random variable.
-The probability of winning a certain lottery is 1/70,366. For people who play 929 times, find the standard deviation for the random variable X, the number of wins.
A)3.5021
B)0.1259
C)0.0132
D)0.1149

Question

Find the standard deviation of the binomial random variable.
-The probability of winning a certain lottery is 1/70,366. For people who play 929 times, find the standard deviation for the random variable X, the number of wins. 
A)3.5021
B)0.1259
C)0.0132
D)0.1149

Quizplus · Accepted Answer

The standard deviation of a binomial random variable is given by the formula $\sqrt{n \cdot p \cdot (1-p)}$, where $n$ is the number of trials and $p$ is the probability of success on a single trial. Here, $n = 929$ and $p = \frac{1}{70366}$. Plugging these values into the formula gives $\sqrt{929 \cdot \frac{1}{70366} \cdot (1 - \frac{1}{70366})}$, which calculates to approximately 0.1149.

Find the Standard Deviation of the Binomial Random Variable