### Create a StudySoup account

#### Be part of our community, it's free to join!

Already have a StudySoup account? Login here

# 204 Class Note for STAT 22500 with Professor Martin at Purdue

### View Full Document

## 45

## 0

## Popular in Course

## Popular in Department

This 2 page Class Notes was uploaded by an elite notetaker on Friday February 6, 2015. The Class Notes belongs to a course at Purdue University taught by a professor in Fall. Since its upload, it has received 45 views.

## Similar to Course at Purdue

## Reviews for 204 Class Note for STAT 22500 with Professor Martin at Purdue

### What is Karma?

#### Karma is the currency of StudySoup.

#### 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 225 7 Conditional Probability Practice Problems Solutions 021109 1 Your keychain holds six keysiexactly one is your house key Suppose you arrive home after dark and cannot see the keys To open the door you randomly try each key until you get the correct one making sure you do not try the same key twice Find the probability that the third key tried is the house key using a counting techniques This experiment can be visualized as laying out the keys in a random order If the third key is to be the correct one then we only have 5 of the 6 positions free to play with There are 51 ways to arrange the other ve keys out of the total of 61 arrangements so the probability is 5161 16 the multiplication rule Let Ak be the event that the k th key tried is correct k 12 6 Then we want to nd PAf A A3 the other three tries don7t matter Using the multiplication rule we have 13qu m A 6 Ag PAiPA lAiPAslAi 4 56 45 14 16 a symmetry argument The correct key has come up on one of the six tries A little re ection about the approach in part a reveals that there is nothing particularly special about the third positionithat is all six of the possible positions would have the same probability Since there are six equal probabilities that must add to 1 the probability can be nothing but 16 2 Suppose you have two decks of cardsione is a standard deck and the other is a trick deck77 that has all Clubs four of each face value a If you pick a card at random from the trick deck whats the probability of selecting an Ace of Clubs Let A be the event that an Ace of Clubs is drawn and T the event that the card was drawn from the trick deck Out of the 52 cards there are 4 Ace of Clubs so the conditional probability is PAlT 452 Suppose you pick one of the two decks at random and then take a random card from the selected deck What is the probability of selecting an Ace of Clubs Use the total probability formula PA PAlTPT PAlT0PT0 45212 15212 5104 c A friend plays the game in b but does not tell you which deck she chose from7 only that she selected an Ace of Clubs What is the probability she drew from the standard deck We want to nd PTclA which we know would require Bayes formula c PAlTCPTC 15212 Pam PM 7 5104 715 3 The Purdue men7s and women7s basketball teams are both playing on the same night Suppose that the men will win with probability 075 and the women with probability 070 The probability that at least one of them will win is 095 a If the women win7 what is the probability that the men will also win Use the de nition of conditional probability and the addition rule PM m W PM PW i PM o W P M W lt l PM PM 075 070 7 095 0714 070 b Are the events M men win and W women win independent Since 0714 31 075 PM7 the two events are not independent

### BOOM! Enjoy Your Free Notes!

We've added these Notes to your profile, click here to view them now.

### You're already Subscribed!

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

#### "There's no way I would have passed my Organic Chemistry class this semester without the notes and study guides I got from StudySoup."

#### "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."

#### "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!"

#### "It's a great way for students to improve their educational experience and it seemed like a product that everybody wants, so all the people participating are winning."

### 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

Satisfaction Guarantee: If you’re not satisfied with your subscription, you can contact us for further help. Contact must be made within 3 business days of your subscription purchase and your refund request will be subject for review.

Please Note: Refunds can never be provided more than 30 days after the initial purchase date regardless of your activity on the site.