<PRE><B>Question 1193400</B>
&lt;font color=black size=3&gt;
Answers: 
Variance = &lt;font color=red&gt;5 (exact)&lt;/font&gt;
Standard Deviation = &lt;font color=red&gt;2.236068 (approximate)&lt;/font&gt;



Explanation:
This is a binomial distribution problem.
n = 20 = sample size
p = 50% = 0.50 = probability a company sends a representative


The variance of this binomial distribution is
v = variance
v = n*p*(1-p)
v = 20*0.50*(1-0.50)
v = &lt;font color=red&gt;5&lt;/font&gt;


The standard deviation is the square root of the variance
sigma = standard deviation
sigma = sqrt(v)
sigma = sqrt(5)
sigma = &lt;font color=red&gt;2.236068&lt;/font&gt;
This is approximate to 6 decimal places. Round it however your teacher instructs.
&lt;/font&gt;</PRE>