Exam 7: Random Variables and Discrete Probability Distributions

NARRBEGIN: Mobile Phones Sales 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. X 1 1 0.4 0.1 2 0.3 0.2 NARREND -{Mobile Phones Sales Narrative} Compare V(X) + V(Y) to V(X + Y). What is your conclusion?

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Question 101

NARRBEGIN: Sports Fans Sports Fans Suppose that past history shows that 5% of college students are sports fans. A sample of 10 students is to be selected.NARREND -{Sports Fans Narrative} A sample of 100 students is to be selected. What is the standard deviation of the number of sports fans you expect?

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Question 102

NARRBEGIN: Mobile Phones Sales 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. X 1 1 0.4 0.1 2 0.3 0.2 NARREND -{Mobile Phones Sales Narrative} Compute the expected number of iPhones sold daily.

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Question 103

The dean of students conducted a survey on campus. Grade point average (GPA) is an example of a(n) ____________________ random variable.

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Question 104

NARRBEGIN: Car Sales Car Sales The joint probability distribution of variables X and Y is shown in the table below. Rebecca and Rachel are car salespeople. Let X denote the number of cars that Rebecca will sell in a month, and let Y denote the number of cars Rachel will sell in a month. X 1 2 3 1 0.30 0.18 0.12 2 0.15 0.09 0.06 3 0.05 0.03 0.02 NARREND -{Car Sales Narrative} Verify that V(X + Y) = V(X) + V(Y). Did you expect this result? Why?

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Question 105

A motorcycle insurance company evaluates many numerical variables about a person before deciding on an appropriate rate for motorcycle insurance. The number of tickets a person has received in the last 3 years is an example of a(n) ____________________ random variable.

(Short Answer)

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Question 106

NARRBEGIN: Sports Fans Sports Fans Suppose that past history shows that 5% of college students are sports fans. A sample of 10 students is to be selected.NARREND -{Sports Fans Narrative} Find the probability that at most 1 student is a sports fan.

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Question 107

The largest value that a Poisson random variable X can have is n.

(True/False)

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Question 108

NARRBEGIN: Mobile Phones Sales 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. X 1 1 0.4 0.1 2 0.3 0.2 NARREND -{Mobile Phones Sales Narrative} Calculate V(X + Y) directly by using the probability distribution of X + Y.

(Short Answer)

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Question 109

Another name for the mean of a probability distribution is its expected value.

(True/False)

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Question 110

NARRBEGIN: Number of Motorcycles Number of Motorcycles The probability distribution of a discrete random variable X is shown below, where X represents the number of motorcycles owned by a family. 0 1 2 3 ( ) 0.25 0.40 0.20 0.15 NARREND -{Number of Motorcycles Narrative} Find the following probabilities: a.P(X > 1) b.P(X $\le$ 2) c.P(1 $\le$ X $\le$ 2) d.P(0 < X < 1) e.P(1 $\le$ X < 3)

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Question 111

The mean of a discrete probability distribution for X is the sum of all possible values of X, divided by the number of possible values of X.

(True/False)

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Question 112

If the probability of success p remains constant in a binomial distribution, an increase in n will increase the variance.

(True/False)

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Question 113

Let X be a Poisson random variable with $\mu$ = 8. Use the table of Poisson probabilities to calculate: a.P(X $\le$ 6) b.P(X = 4) c.P(X $\ge$ 3) d.P(9 $\le$ X $\le$ 14)

(Short Answer)

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Question 114

NARRBEGIN: Unsafe Levels of Radioact 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.NARREND -{Unsafe Levels of Radioactivity Narrative} Find the probability that there will be exactly 3 incidents in a year.

(Short Answer)

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Question 115

The number of female customers out of a random sample of 100 customers arriving at a department store has a binomial distribution.

(True/False)

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Question 116

NARRBEGIN: Golfing Store 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. X 1 2 3 1 0.30 0.18 0.12 2 0.15 0.09 0.06 3 0.05 0.03 0.02 NARREND -{Golfing Store Narrative} Calculate E(XY).

(Short Answer)

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Question 117

The expected number of heads in 250 tosses of an unbiased coin is 125.

(True/False)

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Question 118

The probability of a failure in a binomial experiment is denoted by ____________________.

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Question 119

The number of customers arriving at a department store in a 5-minute period has a binomial distribution.

(True/False)

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Question 120

Showing 101 - 120 of 277

The dean of students conducted a survey on campus. Grade point average (GPA) is an example of a(n) ____________________ random variable.

A motorcycle insurance company evaluates many numerical variables about a person before deciding on an appropriate rate for motorcycle insurance. The number of tickets a person has received in the last 3 years is an example of a(n) ____________________ random variable.

NARRBEGIN: Sports Fans Sports Fans Suppose that past history shows that 5% of college students are sports fans. A sample of 10 students is to be selected.NARREND -{Sports Fans Narrative} Find the probability that at most 1 student is a sports fan.

The largest value that a Poisson random variable X can have is n.

Another name for the mean of a probability distribution is its expected value.

The mean of a discrete probability distribution for X is the sum of all possible values of X, divided by the number of possible values of X.

If the probability of success p remains constant in a binomial distribution, an increase in n will increase the variance.

Let X be a Poisson random variable with $\mu$ = 8. Use the table of Poisson probabilities to calculate: a.P(X $\le$ 6) b.P(X = 4) c.P(X $\ge$ 3) d.P(9 $\le$ X $\le$ 14)

The number of female customers out of a random sample of 100 customers arriving at a department store has a binomial distribution.

The expected number of heads in 250 tosses of an unbiased coin is 125.

The probability of a failure in a binomial experiment is denoted by ____________________.

The number of customers arriving at a department store in a 5-minute period has a binomial distribution.

What Is Statistics

Graphical Descriptive Techniques I

Graphical Descriptive Techniques II

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 Optional

Simple Linear Regression and Correlation

Multiple Regression

Filters

Exam 7: Random Variables and Discrete Probability Distributions

The dean of students conducted a survey on campus. Grade point average (GPA) is an example of a(n) ____________________ random variable.

A motorcycle insurance company evaluates many numerical variables about a person before deciding on an appropriate rate for motorcycle insurance. The number of tickets a person has received in the last 3 years is an example of a(n) ____________________ random variable.

NARRBEGIN: Sports Fans Sports Fans Suppose that past history shows that 5% of college students are sports fans. A sample of 10 students is to be selected.NARREND -{Sports Fans Narrative} Find the probability that at most 1 student is a sports fan.

The largest value that a Poisson random variable X can have is n.

Another name for the mean of a probability distribution is its expected value.

The mean of a discrete probability distribution for X is the sum of all possible values of X, divided by the number of possible values of X.

If the probability of success p remains constant in a binomial distribution, an increase in n will increase the variance.

Let X be a Poisson random variable with μ\muμ = 8. Use the table of Poisson probabilities to calculate: a.P(X ≤\le≤ 6) b.P(X = 4) c.P(X ≥\ge≥ 3) d.P(9 ≤\le≤ X ≤\le≤ 14)

The number of female customers out of a random sample of 100 customers arriving at a department store has a binomial distribution.

The expected number of heads in 250 tosses of an unbiased coin is 125.

The probability of a failure in a binomial experiment is denoted by ____________________.

The number of customers arriving at a department store in a 5-minute period has a binomial distribution.

What Is Statistics

Graphical Descriptive Techniques I

Graphical Descriptive Techniques II

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 Optional

Simple Linear Regression and Correlation

Multiple Regression

Filters

Let X be a Poisson random variable with $\mu$ = 8. Use the table of Poisson probabilities to calculate: a.P(X $\le$ 6) b.P(X = 4) c.P(X $\ge$ 3) d.P(9 $\le$ X $\le$ 14)