185 reputation
10
bio website twitter.com/Pitecantropus80
location Mexico
age 33
visits member for 2 years, 5 months
seen Sep 26 at 21:05

Actuary, finance and risk oriented, musician, programmer...

I enjoy mathematics, probability, statistics, numerical methods... and whatever challenges the creativity of human mind.

Just for information, I've found an article that I think it's important before asking something here (or anywhere else): http://mattgemmell.com/2008/12/08/what-have-you-tried/


Aug
21
awarded  Citizen Patrol
Aug
21
awarded  Critic
Aug
21
comment Which symbol should be used for an empty set?
This is not a constructive question... It's just about "what symbol is better"... it's a matter of preference!
Jun
20
comment Is it wrong to say $ \sqrt{x} \times \sqrt{x} =\pm x,\forall x \in \mathbb{R}$?
Notice that $\sqrt{x^2}=|x|$, so it can be said that $\sqrt{x^2}=\pm x$
Jun
20
answered Sanity check, is $\{(-9,-3),(2,-1),(7,7),(-1,-1)\}$ a function?
Jun
17
revised Is it wrong to say $ \sqrt{x} \times \sqrt{x} =\pm x,\forall x \in \mathbb{R}$?
Corrected: $x\geq0$ instead of $x>0$
Jun
17
comment Is it wrong to say $ \sqrt{x} \times \sqrt{x} =\pm x,\forall x \in \mathbb{R}$?
@Théophile ook... $x\geq0$
Jun
17
answered Is it wrong to say $ \sqrt{x} \times \sqrt{x} =\pm x,\forall x \in \mathbb{R}$?
Jun
7
comment What is the chance to get a parking ticket in half an hour if the chance to get a ticket is 80% in 1 hour?
@MarkAdler Thank you Mark... I will soon correct my answer to include this calculation for the value of $\lambda$. And yes, Math is beautiful! :-)
Jun
6
awarded  Supporter
Jun
5
revised What is the chance to get a parking ticket in half an hour if the chance to get a ticket is 80% in 1 hour?
deleted 6 characters in body
Jun
5
revised What is the chance to get a parking ticket in half an hour if the chance to get a ticket is 80% in 1 hour?
Corrected my answer by calculating 1-Pr{N=0}
Jun
5
comment What is the chance to get a parking ticket in half an hour if the chance to get a ticket is 80% in 1 hour?
That said, I'm correcting my answer, because I calculated the probability of "being spotted" once per interval, which is not what we are looking for. The probability we're looking for is "what is the probability of 'being spotted' at least one time", which is 1 - Pr{"Not 'being spotted'"}.
Jun
5
comment What is the chance to get a parking ticket in half an hour if the chance to get a ticket is 80% in 1 hour?
With no further information, the expected value of the tickets per hour is 0.8 (is a Bernoulli experiment). I think the Poisson Process hypothesis holds because all you know is that you may "get caught" with a given probability in a unit of time. Of course you can't be caught more than once a day, but that doesn't implies that you can't be "spotted" n times a day.
Jun
4
awarded  Teacher
Jun
4
awarded  Editor
Jun
4
revised What is the chance to get a parking ticket in half an hour if the chance to get a ticket is 80% in 1 hour?
Just added the coment about the memoryless property of the Poisson process, and the reference
Jun
4
answered What is the chance to get a parking ticket in half an hour if the chance to get a ticket is 80% in 1 hour?
May
30
awarded  Autobiographer