Currently, an average of 7 residents of the village of Westport (population 760) die each year (based on data from the U.S. National Center for Health Statistics).

a. Find the mean number of deaths per day.

b. Find the probability that on a given day, there are no deaths.

c. Find the probability that on a given day, there is more than one death.

d. Based on the preceding results, should Westport have a contingency plan to handle more than one death per day? Why or why not?

Short Answer

Expert verified

a. The mean number of deaths is 0.0192.

b.The probability that on a given day, there is no death is 0.98.

c. The probability that on a given day, there is more than one death is 0.000182.

d. No, Westport does not need to have a contingency plan to handle more than one death per day.

Step by step solution

01

Given information

On average, 7 residents of the village of Westport (population 760) die each year.

02

Step 2: Compute the mean number of deaths per day

a.

LetX be the number of residents of the village of Westport that die each day.

The mean value for X, that is, the number of deaths each day, is given as

μ=NoofdeathsperyearTotalnumberofdaysinayear=7365=0.0192

Therefore, the mean number of deaths is equal to 0.0192.

03

Compute the probability for no death 

b.

As the occurrences are random, independent, and uniformly distributed on the interval of 365 days of the year, the variable X would follow the Poisson distribution such that the mean is 0.0192.

The probability of no death is given as

Px=μxe-μx!P0=0.019202.71828-0.01920!=0.981

Therefore, the probability that on a given day, there is no death is 0.981.

04

Compute the probability that there is more than one death

c.

The probability of more than one death is given as

Px>1=1-Px=0-Px=1=1-0.019202.71828-0.01920!-0.019212.71828-0.01921!=1-0.981-0.0190.000182

Therefore, the probability that on a given day, there is more than one death is 0.000182.

05

Step 5: Comment if Westport should have a contingency plan to handle more than one death per day

d.

From the above results, the probability of more than one death is very small, that is, lesser than 0.05, which implies that the event is rare.

Therefore, Westport does not need to have a contingency plan to handle more than one death per day.

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

In Exercises 15–20, assume that random guesses are made for eight multiple choice questions on an SAT test, so that there are n = eight trials, each with probability of success (correct) given by p = 0.20. Find the indicated probability for the number of correct answers.

Find the probability that the number x of correct answers is no more than 2.

In Exercises 21–25, refer to the accompanying table, which describes the numbers of adults in groups of five who reported sleepwalking (based on data from “Prevalence and Comorbidity of Nocturnal Wandering In the U.S. Adult General Population,” by Ohayon et al., Neurology, Vol. 78, No. 20).

Find the mean and standard deviation for the numbers of sleepwalkers in groups of five.

x

P(x)

0

0.172

1

0.363

2

0.306

3

0.129

4

0.027

5

0.002

In Exercises 15–20, assume that random guesses are made for eight multiple choice questions on an SAT test, so that there are n = 8 trials, each with probability of success (correct) given by p = 0.20. Find the indicated probability for the number of correct answers.

Find the probability that the number x of correct answers is exactly 7.

In Exercises 7–14, determine whether a probability

distribution is given. If a probability distribution is given, find its mean and standarddeviation. If a probability distribution is not given, identify the requirements that are notsatisfied.

In a survey, cell phone users were asked which ear they use to hear their cell phone, and the table is based on their responses (based on data from “Hemispheric Dominance and Cell Phone Use,” by Seidman et al., JAMA Otolaryngology—Head &Neck Surgery,Vol. 139, No. 5).

P(x)

Left

0.636

Right

0.304

No preference

0.06

Is the random variable given in the accompanying table discreteor continuous? Explain.

Number of Girls x

P(x)

0

0.063

1

0.25

2

0.375

3

0.25

4

0.063

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