Question 1086151
<font color="black" face="times" size="3">This is a Binomial Distribution problem because for any person, there are two outcomes: their phone is left on or it is turned off. Each trial (asking a person whether their phone is on or not) is independent from one another. 


n = Sample size = 61000
p = Probability of success = probability of person leaving phone on = 13.7% = 0.137


Variance = n*p*(1-p)
Variance = 61000*0.137*(1-0.137)
Variance = <font color=red>7212.091</font></font>