## ujuge321 3 years ago Phone calls arrive at the rate of 15 per hour at the reservation desk for a hotel, according to a poisson distribution. If no calls are currently being processed, and the desk employee leaves the desk for a 10-minute break, what is the probability the phone will ring while he is gone on his break?

1. benice

if no calls are being processed is just to throw you off as s poisson distribution is a memoryless property you want to find the prob of zero rings and then take that away from one http://www.youtube.com/watch?v=Fk02TW6reiA this video should explain it

2. ujuge321

i watched that video just now but it did not help at all. Could you write down the solution for me?

3. benice

so we are dealing with a 10min time frame .... find the expected value 1/6*15=2.5|dw:1334385857866:dw|

4. ujuge321

why is it 6*15?

5. benice

10 minutes is 1/6 of an hour .. you are gettin the expected value for that time frame and calling it alpha

6. benice

x=0 as this as said earlier is no call... and we want 1 minus that prob above

7. ujuge321

oh now i understand. Thank you so much. I am suck at poisson distribution problems and it seems like problems are having different patterns.

8. benice

i suck at them too... watch that video again, it helps me

9. ujuge321

okay. I will try. Do you have skype or messenger? I feel like contacting you for math problems.

10. benice

if I'm here ill gladly help.

11. ujuge321

okay.

12. ujuge321

Help me with this another problem. Celina is an executive who receives an average of 8 phone calls each afternoon between 2 and 4. Assuming that the calls are Poisson distributed, what is the probability that celina will receive three or more calls between 2:30 and 3:30?

13. benice

so the average is 4 an hour..... the time frame your dealing with is an hour..... ie2.30-3.30.....

14. benice

so alpha is =4 now P(x>=3)=P(x=3)+P(x=4)+(x=5)...... .alll the way to infinity but life is short so we calculate 1-{P(x=0)+P(x=1)+P(x=2)}

15. ujuge321

Thank you.