1. ## Re:

A nice thing about a Poisson random variable is that its intensity is dimensionally adjustable . lambda = L1/L2 = L1*a/L2*a = lambda2, and asking questions about a Poisson variable with intensity lambda is the same as with lambda2.

lambda = 40planes/10minutes -> P((X ~ Poisson(40/10)) >= 1). Repeat similar procedures for the other problems.

2. so u mean to say that lambada is 40 for this particualr problem??. like 240 / 6 (for a 10 min time interval) is what we did, but using 40 as lambada, we arent able to derive any values from the table

3. This thread's a bit long :O. Work on it and post answer if you'd like verification. You just need a calculator that can compute factorials and evaluate e^x to find poisson probabilities.

4. ok so lambada value here =4

and for the following question

a) atleast 1 plane arrives during the 10-minute time span, the answer is

P (x>=1) = 1 - P (x=0)

P(x=0) = (4^0 * e^-4) / 0! = 0.0183

P (x>=1) = 0.9817

can u verify if the answer is correct

Also, if you can make me more understand, that lambada for 10 minute time span should be 40, and when we calculate lambada=4, it is for a 1 minute time span, why cant we use lambada as 40, as the question is for a 10 minute time span. please explain

6. ## Re:

4plane/min = 40plane/10min, either works as they are identical, you have to adjust your unit of time. If lambda = 40, you're working in 10 minute intervals,etc. I don't see any issue with your computations at first glance, except you'll want to use lambda = 40, again because 10 is your unit of time.

7. thnaks, but with lambda=40, answer is not coming out proper in my opinion...please advise..like if you compute e^-40, its coming something as 10^-18, i doubt if its rite, coz rest

P(x=0) = (40^0 * e^-40) / 0! = 0

P(X>=1) = 1 - P (x=0) = 1 - 0 = 1

probability that atleast 1 plane will come in 10 min interval is 1. is the answer correct

8. ## Beastly!

'Tis the nature of the beast. You have 4 coming in on average every 1 minute, so surely you have at least one coming in every 10 minutes.

9. ok thnx much