Probability of a streak???

[kras]

Hi everybody,

I tried to implemented it by myself but found it impossible. I went to
Help and searched for Monte Carlo simulation. Read everything what I've
found about it, but again, no results. Probably I did the wrong search.

I'll put it this way: If there is X% probability of event A happening
and (1-X)% probability of event B happening, how can I determine the
probability of encountering a streak of (2; 3; 4; etc.) events A,
respectively events B.

For example, I've been told that if event A has probability of 60%,
respectively event B has probability of 40%, this means that there is
13% chance of four consecutive events A and 2-3% chance of four
consecutive events B.

I would like to implement this in excel sheet.

Any help is much appreciated.

kras

 

[Pete_UK]

If the probability of event A is 60% (i.e. 0.6), then the probability
of four consecutive A events is:

0.6 * 0.6 * 0.6 * 0.6 = 0.1296 or 12.96%

If the probability of event B is 40%, then the probability of four
successive B events is:

0.4 * 0.4 * 0.4 * 0.4 which is 0.0256 or 2.56%

So, just multiply the probabilities for each successive event.

Hope this helps.

Pete

 

[joeu2004]

For example, I've been told that if event A has probability of 60%,
respectively event B has probability of 40%, this means that there is
13% chance of four consecutive events A and 2-3% chance of four
consecutive events B. I would like to implement this in excel sheet.

=binomdist(4,4,60%,0) results in 12.96%.
=binomdist(4,4,40%,0) results in 2.56%

This presumes that A and B are mutually-exclusive and the only
possible outcomes, and the probabilities remain the same for all
trials. It also assumes that there are a fixed number of trials, and
the outcome of the trials are independent.

 

[kras]

Thank you both Pete and joeu2004!!!

 

[Pete_UK]

You're welcome.

Pete