SOLUTION: According to a survey, college students make an average of 11 calls per day on their mobile phone. Moreover, 80% of the students surveyed indicated that their parents pay for their

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Question 815715: According to a survey, college students make an average of 11 calls per day on their mobile phone. Moreover, 80% of the students surveyed indicated that their parents pay for their mobile phone expenses.If a student is selected at random, what is the probability that he or she makes:
(i) More than 12 calls in a day?
(ii) Less than the average number of calls in a day?
(iii) More than 15 calls in a day?
(i) P(x≥12)= 1 - P(0) - P(1)....P(12)
= 1- e^(-12).12^0/0! until 12??
its confuse me cause there will be long equation then if that supposed to be? Im very grateful if you can help me with this queation.thank you.

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 
Hi,
According to a survey,
college students make an average of 11 calls per day on their mobile phone.
(i) P ( x > 12)= 0.31130334853593
(ii) P(x < 11) = 0.459888702693687
(iii) P( x > 15)= 0.092603908284245
Poisson Probability Distribution
P(x; A) =+%28e%5E%28-A%29%29+%28A%5Ex%29+%2F+x%21+
| A the average number of successes given
http://stattrek.com/online-calculator/poisson.aspx