In a certain town, 22% of voters favor a given ballot measure. For groups of 21 voters, find the variance for the number who favor the measure.
A) $3.6$ $\text { voters } ^2$
B) 13$\text { voters } ^2$
C) $1.9$ $\text { voters } ^2$
D) $4.6$ $\text { voters } ^2$

Question

In a certain town, 22% of voters favor a given ballot measure. For groups of 21 voters, find the variance for the number who favor the measure. 
A) $3.6$ $\text { voters } ^2$
B) 13$\text { voters } ^2$
C) $1.9$ $\text { voters } ^2$
D) $4.6$ $\text { voters } ^2$

Quizplus · Accepted Answer

The variance for a binomial distribution is calculated using the formula $np(1-p)$, where $n$ is the number of trials (voters) and $p$ is the probability of success (favoring the measure). Here, $n = 21$ and $p = 0.22$. So, the variance is $21 \times 0.22 \times (1 - 0.22) = 3.6$.

In a Certain Town, 22% of Voters Favor a Given 3.63.63.6

In a Certain Town, 22% of Voters Favor a Given $3.6$