Search All of the Math Forum:
Views expressed in these public forums are not endorsed by
NCTM or The Math Forum.


hagman
Posts:
1,923
Registered:
1/29/05


Re: Am I punctual?
Posted:
May 27, 2010 1:17 PM


On 27 Mai, 17:13, musicgold <major_y...@yahoo.com> wrote: > Thanks folks. > > Let just forget about this whole punctual or not situation. I am interested in learning how I can apply my statistics knowledge in everyday situations. Let us just consider a hypothetical situation. > > Everyday, I travel from point A to point B. It is my target is to keep the travel time at one hour. I feel that since the whole process involves many independent activities (variables) walk, bus, train, elevators  there is bound to be some randomness or noise in my travel time. I have a sample of 200 days. > > I wish to know whether it actually takes me one hour to travel from A to B. How should I go about it? > > Also, is there any website where I can read on the application of math/stats in daytoday situations? > > Thanks, > > MG.
For this problem, you would try to determine mean and variance from your sample data (assuming a nice normal distribution). If you obtain, say mu = 58 minutes and sigma = 2 minutes and you want to be at B at 08:00 am with a 3 sigma confidence, you must start at 06:54. If you are satisfied with a 50% chance, starting at 07:02 suffices. If the distribution does not look very normal (or even if it does) you may also simply take the corresponting percentile of your sample data to estimate your chacne of arriving in time.



