My friend was worried about walking across OSU campus because of rape.
I said in the 1 mile walk she probably has a 1 in a million chance of getting raped. But she walks it twice a day, 200 days a year for 4 years, so that is 1600 times she will make that walk.

So the odds are not 1600 out of a mlilion right?
Because if she walked it 1 million times, she isn't going to get raped 100%.

So how do i calculate this?

it's 1 - (1 - 1/1000000) ^ 1600 = 0.16%

so if she does this walk 1 million times, she has a 36.78% chance, did id o that math correct?

1 minus that. so 63.21% chance.

ok i get it! thanks for all the help.

This assumed the odds of a rape are the same no matter what time of day or night, and I have to believe that would have a fairly significant impact on the final estimates.

uh.. yes, but the more obvious fallacy is that the one in a million figure is completely made up.

What?

umm what are your chances of winning the lotto if you buy ONE ticket each week.

7 MILLION to 1.

Next week you buy that same ticket what are your chances

7 MILLION to 1

What happens when you buy two tickets in one week

3.5 MILLION to 1.

Damn, I must be the luckiest person ever. I won the lotto TWICE.

MEGAFORTUNE LOTTERY INTERNATIONAL
INTERNATIONAL PROMOTION/PRIZE AWARD DEPT.
REF: MLI/231-ILGI0431/04
BATCH: IPD/17/096/PTNL
RE: WINNING FINAL NOTIFICATION

Sir/Madam, We are pleased to inform you of the result of the Lottery Winners International programs held on the 17th of January 2005. Your e-mail address attached to ticket number 20511465897-6291 with serial number 472-971103 drew lucky numbers 8-66-97-22-71-64 which consequently won in the 3rd category, you have therefore been approved for a sum pay out of US$ 500,000 000. (five hundred Thousand United States Dollars). CONGRATULATIONS!!!

Due to mix up of some numbers and names, we ask that you keep your winning information very confidential till your claims has been processed and your prize/money Remitted to you. This is part of our security protocol to avoid double claiming and unwarranted abuse of this program by some participants. All participants were selected through a computer ballot system drawn from over 200,000,000 company and 300,000,000 individual email addresses and names from all over the world. This promotional program takes place annually. We hope with part of your winning you will take part in our next year USD10 million international lottery. To file for your claim, please contact our/your fiducial agent MR.PHILIP GERE of the, MECURY TRUST AGENT TEL: +31-621-488-708 FAX: +31-645-236-856 Email: philipgere900@netscape.net Note that all winning must be claimed not later than 3rd of February 2005. After this date all unclaimed, funds will be included in the next stake.

Please note in order to avoid unnecessary delays and complications please remember to quote your reference number and batch numbers in all correspondence. Furthermore, should there be any change of address do inform our agent as soon as possible. Congratulations once more from our members of staff and thank you for being part of our promotional program.

Note: Anybody under the age of 18 is automatically disqualified.

Sincerely yours,
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. REPLY EMAIL TO philipgere900@netscape.net


And then later...

WORLD WIDE INTERNATIONAL STAKE LOTTERY NL
24, ISOLATOR WEG
1055WE AMSTERDAM,
THE NETHERLANDS
FROM:THE DESK OF THE MANAGING DIRECTOR
INTERNATIONAL PROMOTION/PRIZE AWARD DEPT
REF:HW6/315116127/27
BATCH:15/623/GXX.
ATTN:CEO

Dear Winner,

We are pleased to inform you of the result of the Lottery Winners International programs held on the 26/04/2004. Your e-mail address attached to ticket number 883734657492-5319 with serial number 7263-267, batch number 8254297137,lottery ref number 7336065782 and drew lucky numbers 14-22-28-37-40-44 which consequently won in the 1st category, you have therefore been approved for a lump sum pay out of US$ 500,000.00 (Five Hundred Thousand United States Dollars)

CONGRATULATI ONS!!!
Due to mix up of some numbers and names, we ask that you keep your winning information confidential until your claims has been processed and your money Remitted to you. This is part of our security protocol to avoid double claiming and unwarranted abuse of this program by some participants.

All participants were selected through a computer ballot system drawn from over 92,000 companies and 68,000,000 individual email addresses and names from all over the world. This promotional program takes place every year. This lottery was promoted and sponsored by Association of software producers. we hope with part of your winning, you will take part in our next year US$3 Million international lottery. To file for your claim, please contact our fiducial agent MR. VICTOR GRAHAMS of the, ROYAL TRUST AGENCY. TEL: 0031 629 435 359 Email: vgrahamsrta@netscape.net

Remember, all winning must be claimed not later than 30th. of May 2004. After this date all unclaimed funds will be included in the next stake. Please note in order to avoid unnecessary delays and complications, please remember to quote your reference number and batch numbers in all correspondence. Furthermore, should there be any change of address do inform our agent as soon as possible. Congratulations once more from our members of staff and thank you for being part of our promotional program. Note: Anybody under the age of 18 is automatically disqualified.

Yours Sincerely,
Mrs. Hilda Gaspar.
Lottery Co-ordinator.

Jesus, I hope I don't get raped twice tomorrow.

A+

tell her to get a bike and to not dress like a whore and the odds will be astronomical.

You've kept copies of those for 3 and 4 years??? I thought I held on to trash too long.

dude if i won the lottery i'd be keeping the confirmation emails

Level? If not, don't let any Nigerians get ahold of your email address.

a truly random first post i must say, but the point is excellent.

Hilarious. What about the area she is running in Monteroy? Wouldn't that also dramatically skew the completely made up 1 in a million chance?

This result relies on a model, in this case that the probability is constant and the events are independent.

I think a better model in this case is that there are a certain number of rapists looking for victims walking along this route. Even at the largest and most crime-ridden campuses, outdoor rape by a stranger is quite rare. So let's say one OSU student will be a victim of this over the four years. The chance she will be chosen from among women who walk this particular route at these particular times, say is 1 in 10. That implies (given the 1 in a million estimate per trip) that 100,000 trips will be made by women over these four years.

If the friend makes 1,600 of those trips, her chance of being the victim is (1 / 10)*(1,600 / 100,000) = 0.16%.

The breakdown between the probability of the victim being chosen from this route (1 / 10) versus the number of trips made (100,000) doesn't matter. You get the same answer as long as the chance per trip stays at 1 milllion.

What does matter is the assumed number of rapes. If it is very high, then the 1 - (999,999 / 1,000,000)^(1,600) computation is a better estimate. It doesn't make much quantitative difference in this case, you have to make a lot more trips before it really matters a lot.

I think given the arbitrariness of the number 1/1,000,000, the model is within the desired margin of error.

Quantitatively, yes. But no difference is too small to split a hair over.

You need to read about independence my friend.

I think the odds depends on how she looks like..

Sorry, that's contradicted by the evidence. As the saying goes, rape is a crime of violence, not a crime of sex. Rapists don't pick the victims non-rapists are mostly likely to approach in a bar, they pick victims based on a combination of opportunity and their personal demons.

I absolutely refuse to believe looks don't matter.

I'm not talking about the level of attractiveness. But I'm sure girls who look like easier prey with less resistance likely are in a worse position.

Sorry, I understood the original statement differently. I agree looks matter in the sense you mean. People who look confident and alert are less likely to be victims of all sorts of street crimes than people who look passive and confused.