Poisson distribution

During a weekday, heavy lorries pass a census point P on a village high street indepedently and at rondom times. The mean rate for westward travelling lorries is 2 in any 30-minute period, and for eastward travelling lorries is 3 in any 30-minute period. Find the probability

b)that at least one lorry from each direction will pass P in a given 10-minute period.

I have problem in doing part b, I will show my working, thanks a lot for helping.

lambda is now (0.666 + 1) = 1.6666...

P(X>_1) = 1 - (PX=0)
= 1 - (e-1.666)
= 0.8111
But the answer given is 0.308

Can anyone help? Thanks.

Reply 1

RichE

15

authecroix123

b)that at least one lorry from each direction will pass P in a given 10-minute period.

I think you need to reread that bit in bold. :smile:

Reply 2

authecroix123

OP

EDIT: I now know how to do it...thanks.

But I have one more problem. I hope you can give me some clue, thanks again.

1)A large numbers of scredrivers from a trial production run is inspected. It is found that the cellulose acetate handles are defective on 1% and that chrone steel blades are defective on 1.5% of the screwdrivers, the defects occuring independently

b)What is the probability that a sample of 80 contains at least one screwdriver with both a defective handle and a defective blade?

Reply 3

authecroix123

OP

EDIT: I now know how to do it...thanks.

But I have one more problem. I hope you can give me some clue, thanks again.

1)A large numbers of scredrivers from a trial production run is inspected. It is found that the cellulose acetate handles are defective on 1% and that chrone steel blades are defective on 1.5% of the screwdrivers, the defects occuring independently

b)What is the probability that a sample of 80 contains at least one screwdriver with both a defective handle and a defective blade?

I am confused by the question again, I don't really know what it wants.

Reply 4

authecroix123

OP

RichE

I think you need to reread that bit in bold. :smile:

Thanks, I didn't read the question carefully.

Reply 5

nikitha yay

Original post by authecroix123

During a weekday, heavy lorries pass a census point P on a village high street indepedently and at rondom times. The mean rate for westward travelling lorries is 2 in any 30-minute period, and for eastward travelling lorries is 3 in any 30-minute period. Find the probability

b)that at least one lorry from each direction will pass P in a given 10-minute period.

I have problem in doing part b, I will show my working, thanks a lot for helping.

lambda is now (0.666 + 1) = 1.6666...

P(X>_1) = 1 - (PX=0)
= 1 - (e-1.666)
= 0.8111
But the answer given is 0.308

Can anyone help? Thanks.

Could you give a proper full solution?