Question

The number of people arriving for treatment at an emergency room can be modeled by a Poisson process with a rate parameter of six per hour.

(a) What is the probability that exactly four arrivals occur during a particular hour? (Round your answer to three decimal places.)

(b) What is the probability that at least four people arrive during a particular hour? (Round your answer to three decimal places.)

(c) How many people do you expect to arrive during a 45-min period?

Answer 1

My solution is attached

Answer 2

@jim_thompson5910

Answer 3

b and c are wrong. I got a right

Answer 4

I'm getting 0.938 for b as well. Did you make sure to round to only 3 decimal places? I see that you've written out 5 decimal places

Answer 5

oh wait, you were missing a term, you should have P(x = 3) in there as well

Answer 6

When I put the answer in the box i put three = 0.938

Answer 7

you are absolutely right.

Answer 8

since

P(x >= 4) = 1 - P(x < 4)

Answer 9

0.849

Answer 10

as for part c, maybe you just leave it as 4.5 or 4.500 and not round that to 5

Answer 11

I'm getting 0.849 too

Answer 12

okay what about C?

Answer 13

for part c, maybe you just leave it as 4.5 or 4.500 and not round that to 5

Answer 14

but you can't have 4.5 people lol

Answer 15

it's an expected (ie average) number

Answer 16

example

day 1 you have 10 people
day 2 you have 11 people

on average, you have (10+11)/2 = 21/2 = 11.5 people

Answer 17

Thanks that was all right

Answer 18

you're welcome

Answer 19

okay okay lol