Probability in Daily Life
Chapter 1
The Probability in Everyday Life
In This Chapter
Recognizing the prevalence and impact of probability in your everyday life
Taking different approaches to finding probabilities
Steering clear of common probability misconceptions
You’ve heard it, thought it, and said it before: “What are the odds of that happening?” Someone wins the lottery not once, but twice. You accidentally run into a friend you haven’t seen since high school during a vacation in
Florida. A cop pulls you over the one time you forget to put your seatbelt on.
And you wonder . . . what are the odds of this happening? That’s what this book is about: figuring, interpreting, and understanding how to quantify the random phenomena of life. But it also helps you realize the limitations of probability and why probabilities can take you only so far.
In this chapter, you observe the impact of probability on your everyday life and some of the ways people come up with probabilities. You also find out that with probability, situations aren’t always what they seem.
Figuring Out what Probability Means
Probabilities come in many different disguises. Some of the terms people use for probability are chance, likelihood, odds, percentage, and proportion. But the basic definition of probability is the long-term chance that a certain outcome will occur from some random process. A probability is a number between zero and one — a proportion, in other words. You can write it as a percentage, because people like to talk about probability as a percentage chance, or you can put it in the form of odds. The term “odds,” however, isn’t exactly the same as probability. Odds refers to the ratio of the denominator of a probability to the numerator of a probability. For example, if the probability of a horse winning a race is 50 percent (1⁄2), the odds of this horse winning are 2 to 1.
COPYRIGHTED MATERIAL
Understanding the concept of chance
The term chance can take on many meanings. It can apply to an individual
The Probability in Everyday Life
In This Chapter
Recognizing the prevalence and impact of probability in your everyday life
Taking different approaches to finding probabilities
Steering clear of common probability misconceptions
You’ve heard it, thought it, and said it before: “What are the odds of that happening?” Someone wins the lottery not once, but twice. You accidentally run into a friend you haven’t seen since high school during a vacation in
Florida. A cop pulls you over the one time you forget to put your seatbelt on.
And you wonder . . . what are the odds of this happening? That’s what this book is about: figuring, interpreting, and understanding how to quantify the random phenomena of life. But it also helps you realize the limitations of probability and why probabilities can take you only so far.
In this chapter, you observe the impact of probability on your everyday life and some of the ways people come up with probabilities. You also find out that with probability, situations aren’t always what they seem.
Figuring Out what Probability Means
Probabilities come in many different disguises. Some of the terms people use for probability are chance, likelihood, odds, percentage, and proportion. But the basic definition of probability is the long-term chance that a certain outcome will occur from some random process. A probability is a number between zero and one — a proportion, in other words. You can write it as a percentage, because people like to talk about probability as a percentage chance, or you can put it in the form of odds. The term “odds,” however, isn’t exactly the same as probability. Odds refers to the ratio of the denominator of a probability to the numerator of a probability. For example, if the probability of a horse winning a race is 50 percent (1⁄2), the odds of this horse winning are 2 to 1.
COPYRIGHTED MATERIAL
Understanding the concept of chance
The term chance can take on many meanings. It can apply to an individual