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) $3.6$ voters ${ } ^ { 2 }$
B) $4.6$ voters $^ { 2 }$
C) $1.9$ voters $^ { 2 }$
D) 13 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) $3.6$ voters ${ } ^ { 2 }$
B) $4.6$ voters $^ { 2 }$
C) $1.9$ voters $^ { 2 }$
D) 13 voters $^ { 2 }$

Quizplus · Accepted Answer

The variance is the product of the population proportion and the complement of the population proportion, multiplied by the sample size. In this case, the population proportion is 0.22, the complement of the population proportion is 1 - 0.22 = 0.78, and the sample size is 21. Therefore, the variance is 0.22 * 0.78 * 21 = 3.6 voters^2.

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

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