×

### Let's log you in.

or

Don't have a StudySoup account? Create one here!

×

or

16

0

3

# Class Note for STAT 427 at OSU

Marketplace > Ohio State University > Class Note for STAT 427 at OSU

No professor available

These notes were just uploaded, and will be ready to view shortly.

Either way, we'll remind you when they're ready :)

Get a free preview of these Notes, just enter your email below.

×
Unlock Preview

COURSE
PROF.
No professor available
TYPE
Class Notes
PAGES
3
WORDS
KARMA
25 ?

## Popular in Department

This 3 page Class Notes was uploaded by an elite notetaker on Friday February 6, 2015. The Class Notes belongs to a course at Ohio State University taught by a professor in Fall. Since its upload, it has received 16 views.

×

## Reviews for Class Note for STAT 427 at OSU

×

×

### What is Karma?

#### You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 02/06/15
Stat 427 Example of Unauthorized Entrance to a Secure Area Consider the situation where a bank ATM cash withdrawal security system involves keying in a valid K digit account number which if accepted is followed by electronic scanning and recognition of the customer s right thumb print In order for an unauthorized individual to fraudulently withdraw cash they would have to A guess a valid K digit ID number let PrID denote the probability of this event occurring B successfully pass the electronic thumb print scanning process let PTPdenote the probability of this event Assuming that these two events are independent then the probability of fraudulently withdrawing cash FW denoted by PFWwould be calculated as PFW PIDXPTP Calculation of PFW assuming K is known and N attempts are made to guess the ID Under the assumption that the individual knows the ID length K and walks away after they obtain a valid ID but fail to pass the thumb print scan the PFW can be calculated exactly as follows Let N be the number of attempts allowed by an unauthorized user to randomly select a valid ID of length K Consider the following sequence of mutually exclusive events A1 unauthorized user randomly selects a valid ID of length K on the first attempt A2 unauthorized user fails to select a valid ID on the first attempt and randomly selects a valid ID on the second attempt AN unauthorized user fails to select a valid ID on the first Nl attempts and successfully selects a valid ID on the Nth attempt The probability of successfully selecting a valid ID given N possible attempts is given by N PID 2 HA i1 Let CSID denote the event of correctly selecting a valid ID at random on a single attempt Let PCSID denote the probability of correctly selecting a valid ID at random on a single attempt Assuming sampling from the population of all possible ID s with replacement ie ignoring the negligible finite correction factor that would be required if the sampling was done without replacement then 1 fraudcashwdexampledoc M 10K PCSID where M is the number of valid ID s in the bank s database Let CSID denote the complimentary event of failing to select a valid ID at random on a single attempt then M PCSID 1 0K It follows that fori l 2 N M M P A 1 quot1 X 10K 10K Therefore N M N M i PIDZPA K ZIP K 1 i1 10 i1 10 The unconditional probability of fraudulent withdrawal is therefore given by PFWgt11lt Z1 N KHXPTP Notice that this equation involves two probabilities PID and PTP The probability PID involves three parameters M K and N which are known and in fact K can be set by bank management This probability equation can be used to perform sensitivity analyses to determine how sensitive PFW is to the values of M K and PTP This equation can be studied to determine the appropriate values for K to reduce the probability of fraudulent withdrawals to acceptable levels Figures 1 and 2 are examples of this type of analysis for the evaluation of the effect of the model parameters on PID 2 fraudcashwdexampledoc Scatterplot of PID vs K N123456789m 131 9 5 m m 300 m m C K 0 0 0 1 7 M 0 8 6 4 2 1 0 0 0 0 EU Scatterplot of PID vs K N12345678 11 9m u 3 10000 Customers M 10 08 fraudcashwdexampledoc

×

×

### BOOM! Enjoy Your Free Notes!

×

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

## Why people love StudySoup

Bentley McCaw University of Florida

#### "I was shooting for a perfect 4.0 GPA this semester. Having StudySoup as a study aid was critical to helping me achieve my goal...and I nailed it!"

Jennifer McGill UCSF Med School

#### "Selling my MCAT study guides and notes has been a great source of side revenue while I'm in school. Some months I'm making over \$500! Plus, it makes me happy knowing that I'm helping future med students with their MCAT."

Steve Martinelli UC Los Angeles

Forbes

#### "Their 'Elite Notetakers' are making over \$1,200/month in sales by creating high quality content that helps their classmates in a time of need."

Become an Elite Notetaker and start selling your notes online!
×

### Refund Policy

#### STUDYSOUP CANCELLATION POLICY

All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email support@studysoup.com

#### STUDYSOUP REFUND POLICY

StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here: support@studysoup.com

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to support@studysoup.com