Hi, I need help with this problem: On average, 2 students per hour come into the class. What is the probability that the time between two consecutive arrivals is in the interval <10 minutes; 50 minutes>. I don't understand what exactly I have to solve...the probability that 2 students come within 40 minutes? I don't know how to do the first step. Thank you!
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Probability Q: "On average, 2 students per hour come into the class...."
- Thread starter juno88
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HallsofIvy
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What probability distribution are you using? There are many different ways "2 students per hour come into the class". For example, it might well be that the two students always show up "on the hour". In that case the probability the time interval between the arrival of two students in between 10 and 50 minutes is 0. Perhaps you are assuming a uniform distribution. In that case the probability the time between the arrival of two students is between 10 and 50 minutes is (50- 10)/60= 40/60= 2/3.
What probability distribution are you using? There are many different ways "2 students per hour come into the class". For example, it might well be that the two students always show up "on the hour". In that case the probability the time interval between the arrival of two students in between 10 and 50 minutes is 0. Perhaps you are assuming a uniform distribution. In that case the probability the time between the arrival of two students is between 10 and 50 minutes is (50- 10)/60= 40/60= 2/3.
I'm using the Poisson distribution:
p(k)=P(Y=k)=((lambda*t)^k*(e^-lambda*t)/k!
I've tried: k=2, lambda=4/3 and t=40/60=2/3 but the result is wrong (the right result is 0,528)