SOLUTION: The AIRLINE PILOTS AND PASSENGERS ASSOCIATION It has determined that 13.7% of all passengers leave their cell phones on when instructed to turn them off. This was a recent problem

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Question 1086151: The AIRLINE PILOTS AND PASSENGERS ASSOCIATION It has determined that 13.7% of all passengers leave their cell phones on when instructed to turn them off. This was a recent problem when the Galaxy batteries were exploding. From their survey of 61,000 passengers find the variance of the number of passengers who left their phones on.
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
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 = 7212.091