Exam 7: Random Variables and Discrete Probability Distributions

Mobile Phones Sales After analyzing sales data,the owner of a Mobile Phone store produced the following joint probability distribution of the number of iPhones (X)and Blackberries (Y)sold daily. -{Mobile Phones Sales Narrative} Calculate E(X + Y)directly by using the probability distribution of X + Y.

(Short Answer)

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Question 41

Risky Undertaking Suppose you make a $2,000 investment in a risky undertaking.There is a 50% chance that the payoff from the investment will be $5,000,a 20% chance that you will just get your money back,and a 30% chance that you will receive nothing at all from your investment. -{Risky Undertaking Narrative} If you invest $6,000 in the risky undertaking instead of $2,000 and the possible payoffs triple accordingly,what are the expected value of the net profit from the $6,000 investment?

(Essay)

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Question 42

Mobile Phones Sales After analyzing sales data,the owner of a Mobile Phone store produced the following joint probability distribution of the number of iPhones (X)and Blackberries (Y)sold daily. -{Mobile Phones Sales Narrative} Compare V(X)+ V(Y)to V(X + Y).What is your conclusion?

(Essay)

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Question 43

Golfing Store The joint probability distribution of variables X and Y is shown in the table below,where X is the number of drivers and Y is the number of putters sold daily in a small golfing store. -{Golfing Store Narrative} Verify that V(X + Y)= V(X)+ V(Y).Did you expect this result? Why?

(Essay)

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Question 44

If X and Y are independent random variables,which of the following identities is false?

(Multiple Choice)

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Question 45

Unsafe Levels of Radioactivity The number of incidents at a nuclear power plant has a Poisson distribution with a mean of 6 incidents per year. -{Unsafe Levels of Radioactivity Narrative} Find the probability that there will be at least 3 incidents in a year.

(Short Answer)

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Question 46

Gym Visits Let X represent the number of times a student visits a gym in a one month period.Assume that the probability distribution of X is as follows: -{Gym Visits Narrative} What is the probability that the student visits the gym at most twice in a month?

(Short Answer)

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Question 47

The sum of the expected values always equals the expected value of the sums.

(True/False)

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Question 48

Returns on Investment An analysis of the stock market produces the following information about the returns of two stocks. Assume that the returns are positively correlated with correlation coefficient of 0.80. -{Returns on Investment Narrative} Find the mean of the return on a portfolio consisting of an equal investment in each of the two stocks.

(Essay)

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Question 49

If X has a binomial distribution with n = 4 and p = 0.3,find P(X = 1).

(Short Answer)

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Question 50

The standard deviation of a binomial random variable X is given by the formula σ² = np(1 − p),where n is the number of trials,and p is the probability of success.

(True/False)

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Question 51

Given a Poisson random variable X,where the average number of successes occurring in a specified interval is 1.8,then P(X = 0)is:

(Multiple Choice)

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Question 52

Gym Visits Let X represent the number of times a student visits a gym in a one month period.Assume that the probability distribution of X is as follows: -{Gym Visits Narrative} Find the mean and the standard deviation of Y = 2X − 1.

(Essay)

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Question 53

A function or rule that assigns a numerical value to each outcome of an experiment is called:

(Multiple Choice)

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Question 54

Mobile Phones Sales After analyzing sales data,the owner of a Mobile Phone store produced the following joint probability distribution of the number of iPhones (X)and Blackberries (Y)sold daily. -{Mobile Phones Sales Narrative} Find the marginal probability distribution of the number of Blackberries sold daily.

(Essay)

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Question 55

The portfolio expected return of two investments:

(Multiple Choice)

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Question 56

Number of Birds Alana and Eva are sisters.Let X denote the number of birds that Alana may have in the next two years,and let Y denote the number of birds Eva may have during the same period.The marginal probability distributions of X and Y are shown below. -{Number of Birds Narrative} Verify that V(X + Y)= V(X)+ V(Y).Did you expect this result? Why?

(Essay)

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Question 57

An auto insurance company evaluates many numerical variables about a person before deciding on an appropriate rate for automobile insurance.The number of claims a person has made in the last 3 years is an example of a(n)____________________ random variable.

(Short Answer)

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Question 58

A(n)____________________ distribution provides probabilities of combinations of two random variables.

(Short Answer)

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Question 59

Number of Birds Alana and Eva are sisters.Let X denote the number of birds that Alana may have in the next two years,and let Y denote the number of birds Eva may have during the same period.The marginal probability distributions of X and Y are shown below. -{Number of Birds Narrative} Compute the coefficient of correlation between X and Y.Did you expect this result? Why?

(Essay)

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Question 60

Showing 41 - 60 of 283

Mobile Phones Sales After analyzing sales data,the owner of a Mobile Phone store produced the following joint probability distribution of the number of iPhones (X)and Blackberries (Y)sold daily. -{Mobile Phones Sales Narrative} Compare V(X)+ V(Y)to V(X + Y).What is your conclusion?

Golfing Store The joint probability distribution of variables X and Y is shown in the table below,where X is the number of drivers and Y is the number of putters sold daily in a small golfing store. -{Golfing Store Narrative} Verify that V(X + Y)= V(X)+ V(Y).Did you expect this result? Why?

If X and Y are independent random variables,which of the following identities is false?

Unsafe Levels of Radioactivity The number of incidents at a nuclear power plant has a Poisson distribution with a mean of 6 incidents per year. -{Unsafe Levels of Radioactivity Narrative} Find the probability that there will be at least 3 incidents in a year.

Gym Visits Let X represent the number of times a student visits a gym in a one month period.Assume that the probability distribution of X is as follows: -{Gym Visits Narrative} What is the probability that the student visits the gym at most twice in a month?

The sum of the expected values always equals the expected value of the sums.

If X has a binomial distribution with n = 4 and p = 0.3,find P(X = 1).

The standard deviation of a binomial random variable X is given by the formula σ² = np(1 − p),where n is the number of trials,and p is the probability of success.

Given a Poisson random variable X,where the average number of successes occurring in a specified interval is 1.8,then P(X = 0)is:

Gym Visits Let X represent the number of times a student visits a gym in a one month period.Assume that the probability distribution of X is as follows: -{Gym Visits Narrative} Find the mean and the standard deviation of Y = 2X − 1.

A function or rule that assigns a numerical value to each outcome of an experiment is called:

The portfolio expected return of two investments:

An auto insurance company evaluates many numerical variables about a person before deciding on an appropriate rate for automobile insurance.The number of claims a person has made in the last 3 years is an example of a(n)____________________ random variable.

A(n)____________________ distribution provides probabilities of combinations of two random variables.

What Is Statistics

Graphical Descriptive Techniques 1

Graphical Descriptive Techniques 2

Numerical Descriptive Techniques

Data Collection and Sampling

Probability

Continuous Probability Distributions

Sampling Distributions

Introduction to Estimation

Introduction to Hypothesis Testing

Inference About a Population

Inference About Comparing Two Populations

Analysis of Variance

Chi-Squared Tests

Simple Linear Regression and Correlation

Multiple Regression

Model Building

Nonparametric Statistics

Time-Series Analytics and Forecasting

Statistical Process Control

Decision Analysis

Conclusion

Filters

Exam 7: Random Variables and Discrete Probability Distributions

Mobile Phones Sales After analyzing sales data,the owner of a Mobile Phone store produced the following joint probability distribution of the number of iPhones (X)and Blackberries (Y)sold daily. ​ ​ -{Mobile Phones Sales Narrative} Compare V(X)+ V(Y)to V(X + Y).What is your conclusion?

Golfing Store The joint probability distribution of variables X and Y is shown in the table below,where X is the number of drivers and Y is the number of putters sold daily in a small golfing store. ​ ​ -{Golfing Store Narrative} Verify that V(X + Y)= V(X)+ V(Y).Did you expect this result? Why?

If X and Y are independent random variables,which of the following identities is false?

Unsafe Levels of Radioactivity The number of incidents at a nuclear power plant has a Poisson distribution with a mean of 6 incidents per year. ​ ​ -{Unsafe Levels of Radioactivity Narrative} Find the probability that there will be at least 3 incidents in a year.

Gym Visits Let X represent the number of times a student visits a gym in a one month period.Assume that the probability distribution of X is as follows: ​ ​ -{Gym Visits Narrative} What is the probability that the student visits the gym at most twice in a month?

The sum of the expected values always equals the expected value of the sums.

If X has a binomial distribution with n = 4 and p = 0.3,find P(X = 1).

The standard deviation of a binomial random variable X is given by the formula σ2 = np(1 − p),where n is the number of trials,and p is the probability of success.

Given a Poisson random variable X,where the average number of successes occurring in a specified interval is 1.8,then P(X = 0)is:

Gym Visits Let X represent the number of times a student visits a gym in a one month period.Assume that the probability distribution of X is as follows: ​ ​ -{Gym Visits Narrative} Find the mean and the standard deviation of Y = 2X − 1.

A function or rule that assigns a numerical value to each outcome of an experiment is called:

The portfolio expected return of two investments:

An auto insurance company evaluates many numerical variables about a person before deciding on an appropriate rate for automobile insurance.The number of claims a person has made in the last 3 years is an example of a(n)____________________ random variable.

A(n)____________________ distribution provides probabilities of combinations of two random variables.

What Is Statistics

Graphical Descriptive Techniques 1

Graphical Descriptive Techniques 2

Numerical Descriptive Techniques

Data Collection and Sampling

Probability

Continuous Probability Distributions

Sampling Distributions

Introduction to Estimation

Introduction to Hypothesis Testing

Inference About a Population

Inference About Comparing Two Populations

Analysis of Variance

Chi-Squared Tests

Simple Linear Regression and Correlation

Multiple Regression

Model Building

Nonparametric Statistics

Time-Series Analytics and Forecasting

Statistical Process Control

Decision Analysis

Conclusion

Filters

Mobile Phones Sales After analyzing sales data,the owner of a Mobile Phone store produced the following joint probability distribution of the number of iPhones (X)and Blackberries (Y)sold daily. -{Mobile Phones Sales Narrative} Compare V(X)+ V(Y)to V(X + Y).What is your conclusion?

Golfing Store The joint probability distribution of variables X and Y is shown in the table below,where X is the number of drivers and Y is the number of putters sold daily in a small golfing store. -{Golfing Store Narrative} Verify that V(X + Y)= V(X)+ V(Y).Did you expect this result? Why?

Unsafe Levels of Radioactivity The number of incidents at a nuclear power plant has a Poisson distribution with a mean of 6 incidents per year. -{Unsafe Levels of Radioactivity Narrative} Find the probability that there will be at least 3 incidents in a year.

Gym Visits Let X represent the number of times a student visits a gym in a one month period.Assume that the probability distribution of X is as follows: -{Gym Visits Narrative} What is the probability that the student visits the gym at most twice in a month?

The standard deviation of a binomial random variable X is given by the formula σ² = np(1 − p),where n is the number of trials,and p is the probability of success.

Gym Visits Let X represent the number of times a student visits a gym in a one month period.Assume that the probability distribution of X is as follows: -{Gym Visits Narrative} Find the mean and the standard deviation of Y = 2X − 1.