On average I receive one text message every 10.3 hours. Assuming that the time between successive text messages has an exponential distribution, what is the probability that I have to wait between 11 and 21 hours for the next message to arrive?
2007-03-11 09:39:02 · 9 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
Go and get some sleep, but to answer, the probability is high.
2007-03-14 14:34:46 · answer #1 · answered by Hi 7 · 0⤊ 2⤋
The probability density function (pdf, for short) for exponential distribution is:
1 / b * e ^ (- x / b), for x => 0 and 0 for x < 0.
Since E(X) is 10.3, and E(X) = b with exponential distribution, you have everything you need to form pdf:
f(x) = 1 / 10.3 * e (- x / 10.3)
All you need to do now is to integrate it, where the integration area is 11 to 21.
2007-03-11 18:18:47 · answer #2 · answered by Dan Lobos 2 · 0⤊ 0⤋
Thats why you only get 1 message every 10.3 hours. For asking questions like that.
2007-03-11 16:55:39 · answer #3 · answered by truth_and_time_tells_all 6 · 0⤊ 1⤋
The probability is I think evens - or 50 /50
2007-03-11 16:52:30 · answer #4 · answered by Wantstohelpu 3 · 0⤊ 0⤋
How can you base probability on average without knowing what the average was made up from..?
2007-03-11 18:02:51 · answer #5 · answered by Merovingian 6 · 0⤊ 0⤋
0.25 mate
It could be under 11 or 11-21 or 21+ or never
2007-03-12 11:59:15 · answer #6 · answered by Sluugy 5 · 0⤊ 1⤋
SAD, SAD boy GO take a tablet, then lie down and don't ever get up again.
2007-03-11 16:47:38 · answer #7 · answered by Anonymous · 0⤊ 1⤋
Go watch the sunset!
2007-03-11 16:45:26 · answer #8 · answered by Anonymous · 0⤊ 1⤋
I think you have too much time on your hands...
2007-03-11 16:41:55 · answer #9 · answered by Funky Little Spacegirl 6 · 2⤊ 1⤋