Dogs and cats In one large city, 40%of all households own a dog, 32% own a cat, and 18% own both. Suppose we randomly select a household. What’s the probability that the household owns a dog or a cat?

Short Answer

Expert verified

The likelihood that the household owns either a dog or a cat is0.54

Step by step solution

01

Given Information

We have to find the probability that either a dog or a cat is owned by the household.

02

Simplification

Dogs are owned by 40%of all households.
Cats are owned by 32%of all households.
Households with dogs and cats account for 18%of all households.

The likelihood that the household owns a dog or a cat can be estimated as follows:

P(Eitherdogorcat)=P(Dog)+P(Cat)P(DogandCat)=0.40+0.320.18=0.54

Thus, the required probability is0.54

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Mystery box Ms. Tyson keeps a Mystery Box in her classroom. If a student meets expectations for behavior, she or he is allowed to draw a slip of paper without looking. The slips are all of equal size, are well mixed, and have the name of a prize written on them. One of the “prizes”—extra homework—isn’t very desirable! Here is the probability model for the prizes a student can win:

a. Explain why this is a valid probability model.

b. Find the probability that a student does not win extra homework.

c. What’s the probability that a student wins candy or a homework pass?

Is this your card? A standard deck of playing cards (with jokers removed) consists of 52 cards in four suits—clubs, diamonds, hearts, and spades. Each suit has 13 cards, with denominations ace, 2, 3, 4, 5, 6, 7, 8, 9, 10, jack, queen, and king. The jacks, queens, and kings are referred to as “face cards.” Imagine that we shuffle the deck thoroughly and deal one card. The two-way table summarizes the sample space for this chance process based on whether or not the card is a face card and whether or not the card is a heart.

Type of card

Face cardNon-Face cardTotal
Heart3
10
13
Non-Heart9
30
39
Total12
40
52

Are the events “heart” and “face card” independent? Justify your answer.

Liar, liar! Sometimes police use a lie detector test to help determine whether a suspect is

telling the truth. A lie detector test isn’t foolproof—sometimes it suggests that a person is

lying when he or she is actually telling the truth (a “false positive”). Other times, the test

says that the suspect is being truthful when he or she is actually lying (a “false negative”).

For one brand of lie detector, the probability of a false positive is 0.08.

a. Explain what this probability means.

b. Which is a more serious error in this case: a false positive or a false negative? Justify

your answer.

Tall people and basketball players Select an adult at random. Define events T: person is over 6feet tall, and

B: person is a professional basketball player. Rank the following probabilities from smallest to largest. Justify your answer.

P(T)P(B)P(TB)P(BT)

Random assignment Researchers recruited 20volunteers-8men and 12women-to take part in an experiment. They randomly assigned the subjects into two groups of 10people each. To their surprise, 6of the 8men were randomly assigned to the same treatment. Should they be surprised? We want to design a simulation to estimate the probability that a proper random assignment would result in 6or more of the 8men ending up in the same group.

Get 20identical slips of paper. Write "M" on 8of the slips and "W" on the remaining 12slips. Put the slips into a hat and mix well. Draw 10of the slips without looking and place into one pile representing Group 1. Place the other 10slips in a pile representing Group 2. Record the largest number of men in either of the two groups from this simulated random assignment. Repeat this process many, many times. Find the percent of trials in which 6or more men ended up in the same group.

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free