Question 1

The variance Var(x) for the binomial distribution is given by equation

Accepted Answer

A)  np(n - 1). 
B)  np(1 - np). 
C)  n(1 - p). 
D)  np(1 - p). 
A)  np(n - 1). 
B)  np(1 - np). 
C)  n(1 - p). 
D)  np(1 - p).

Question 2

The following table shows part of the probability distribution for the number of boats sold daily at Boats Unlimited. It is known that the average number of boats sold daily is 1.57.   ​
Compute the variance and the standard deviation for this probability distribution.

Accepted Answer

Variance = 1.4051, S

Question 3

Consider the probability distribution below.   ​ The expected value of x equals

Accepted Answer

A)  23. 
B)  25. 
C)  30. 
D)  100. 
A)  23. 
B)  25. 
C)  30. 
D)  100.

Question 4

A cosmetics salesperson, who calls potential customers to sell her products, has determined that 30% of her telephone calls result in a sale. Determine the probability distribution for her next three calls. Note that the next three calls could result in 0, 1, 2, or 3 sales.

Accepted Answer

The answer of A cosmetics salesperson, who calls potential customers...

Question 5

The expected value for a binomial distribution is given by equation

Accepted Answer

A)  (n - 1)(1 - p). 
B)  n(1 - p). 
C)  np. 
D)  (n - 1)p. 
A)  (n - 1)(1 - p). 
B)  n(1 - p). 
C)  np. 
D)  (n - 1)p.

Question 6

A description of the distribution of the values of a random variable and their associated probabilities is called a

Accepted Answer

A)  probability distribution. 
B)  empirical discrete distribution. 
C)  bivariate distribution. 
D)  table of binomial probability. 
A)  probability distribution. 
B)  empirical discrete distribution. 
C)  bivariate distribution. 
D)  table of binomial probability.

Question 7

Roth is a computer-consulting firm. The number of new clients that they have obtained each month has ranged from 0 to 6. The number of new clients has the probability distribution that is shown below.   ​ The expected number of new clients per month is

Accepted Answer

A)  6. 
B)  0. 
C)  3.1. 
D)  3. 
A)  6. 
B)  0. 
C)  3.1. 
D)  3.

Question 8

A production process produces 2.5% defective parts. A sample of five parts from the production process is selected. What is the probability that the sample contains exactly two defective parts?

Accepted Answer

A)  0.2637 
B)  0.0058 
C)  0.0000 
D)  0.0250 
A)  0.2637 
B)  0.0058 
C)  0.0000 
D)  0.0250

Question 9

To compute the probability that in a random sample of n elements, selected without replacement, we will obtain x successes, we would use the _____ probability distribution.

Accepted Answer

A)  binomial 
B)  Poisson 
C)  hypergeometric 
D)  exponential 
A)  binomial 
B)  Poisson 
C)  hypergeometric 
D)  exponential

Question 10

Consider the probability distribution below.   ​ The variance of x equals

Accepted Answer

A)  9. 
B)  23. 
C)  81. 
D)  610. 
A)  9. 
B)  23. 
C)  81. 
D)  610.

Question 11

Which of the following is a required condition for a discrete probability function?

Accepted Answer

A)  f(x)   0 for all values of x 
B)  ∑f(x) = 1 for all values of x 
C)  ∑f(x) = 0 for all values of x 
D)  ∑f(x)   1 for all values of x 
A)  f(x)   0 for all values of x 
B)  ∑f(x) = 1 for all values of x 
C)  ∑f(x) = 0 for all values of x 
D)  ∑f(x)   1 for all values of x

Question 12

The expected value of a random variable is

Accepted Answer

A)  the value of the random variable that should be observed on the next repeat of the experiment. 
B)  the value of the random variable that occurs most frequently. 
C)  the square root of the variance. 
D)  None of these alternatives is correct. 
A)  the value of the random variable that should be observed on the next repeat of the experiment. 
B)  the value of the random variable that occurs most frequently. 
C)  the square root of the variance. 
D)  None of these alternatives is correct.

Question 13

Roth is a computer-consulting firm. The number of new clients that they have obtained each month has ranged from 0 to 6. The number of new clients has the probability distribution that is shown below.   ​ The variance is

Accepted Answer

A)  1.45. 
B)  2.09. 
C)  3.1. 
D)  9.61. 
A)  1.45. 
B)  2.09. 
C)  3.1. 
D)  9.61.

Question 14

The binomial probability distribution is most symmetric when​

Accepted Answer

A)  ​n is 30 or greater. 
B)  ​n equals p. 
C)  ​p approaches 1. 
D)  ​p equals 0.5. 
A)  ​n is 30 or greater. 
B)  ​n equals p. 
C)  ​p approaches 1. 
D)  ​p equals 0.5.

Question 15

The use of the relative frequency method to develop discrete probability distributions leads to what is called a _____ discrete distribution.

Accepted Answer

A)  binomial 
B)  empirical 
C)  non-uniform 
D)  uniform 
A)  binomial 
B)  empirical 
C)  non-uniform 
D)  uniform

Question 16

A random variable that may take on any value in an interval or collection of intervals is known as a _____ random variable.

Accepted Answer

A)  continuous 
B)  discrete 
C)  mixed type 
D)  multivariate 
A)  continuous 
B)  discrete 
C)  mixed type 
D)  multivariate

Question 17

An experiment consists of determining the speed of automobiles on a highway by the use of radar equipment. The random variable in this experiment is a _____ random variable.

Accepted Answer

A)  discrete 
B)  continuous 
C)  mixed type 
D)  multivariate 
A)  discrete 
B)  continuous 
C)  mixed type 
D)  multivariate

Question 18

The number of electrical outages in a city varies from day to day. Assume that the number of electrical outages (x) in the city has the following probability distribution. ​   ​
The mean and the standard deviation for the number of electrical outages (respectively) are
​

Accepted Answer

A)  2.6 and 5.77. 
B)  0.26 and 0.577. 
C)  3 and 0.01. 
D)  0 and 0.8. 
A)  2.6 and 5.77. 
B)  0.26 and 0.577. 
C)  3 and 0.01. 
D)  0 and 0.8.

Question 19

If one wanted to find the probability of ten customer arrivals in an hour at a service station, one would generally use the _____ probability distribution.

Accepted Answer

A)  binomial 
B)  Poisson 
C)  hypergeometric 
D)  exponential 
A)  binomial 
B)  Poisson 
C)  hypergeometric 
D)  exponential

Question 20

A sample of 2,500 people was asked how many cups of coffee they drink in the morning. You are given the following sample information.   ​ The expected number of cups of coffee is

Accepted Answer

A)  1. 
B)  1.24. 
C)  1.5. 
D)  1.03. 
A)  1. 
B)  1.24. 
C)  1.5. 
D)  1.03.

Exam 5: Discrete Probability Distributions

The variance Var(x) for the binomial distribution is given by equation

The following table shows part of the probability distribution for the number of boats sold daily at Boats Unlimited. It is known that the average number of boats sold daily is 1.57. ​ Compute the variance and the standard deviation for this probability distribution.

Consider the probability distribution below. ​ The expected value of x equals

A cosmetics salesperson, who calls potential customers to sell her products, has determined that 30% of her telephone calls result in a sale. Determine the probability distribution for her next three calls. Note that the next three calls could result in 0, 1, 2, or 3 sales.

The expected value for a binomial distribution is given by equation

A description of the distribution of the values of a random variable and their associated probabilities is called a

Roth is a computer-consulting firm. The number of new clients that they have obtained each month has ranged from 0 to 6. The number of new clients has the probability distribution that is shown below. ​ The expected number of new clients per month is

A production process produces 2.5% defective parts. A sample of five parts from the production process is selected. What is the probability that the sample contains exactly two defective parts?

To compute the probability that in a random sample of n elements, selected without replacement, we will obtain x successes, we would use the _____ probability distribution.

Consider the probability distribution below. ​ The variance of x equals

Which of the following is a required condition for a discrete probability function?

The expected value of a random variable is

Roth is a computer-consulting firm. The number of new clients that they have obtained each month has ranged from 0 to 6. The number of new clients has the probability distribution that is shown below. ​ The variance is

The binomial probability distribution is most symmetric when​

The use of the relative frequency method to develop discrete probability distributions leads to what is called a _____ discrete distribution.

A random variable that may take on any value in an interval or collection of intervals is known as a _____ random variable.

An experiment consists of determining the speed of automobiles on a highway by the use of radar equipment. The random variable in this experiment is a _____ random variable.

The number of electrical outages in a city varies from day to day. Assume that the number of electrical outages (x) in the city has the following probability distribution. ​ ​ The mean and the standard deviation for the number of electrical outages (respectively) are ​

If one wanted to find the probability of ten customer arrivals in an hour at a service station, one would generally use the _____ probability distribution.

A sample of 2,500 people was asked how many cups of coffee they drink in the morning. You are given the following sample information. ​ The expected number of cups of coffee is

Data and Statistics

Descriptive Statistics: Tabular and Graphical Displays

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Introduction to Probability

Continuous Probability Distributions

Sampling and Sampling Distributions

Interval Estimation

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Inference About Means and Proportions With Two Populations

Inferences About Population Variances

Comparing Multiple Proportions, Tests of Independence and Goodness of Fit

Experimental Design and Analysis of Variance

Simple Linear Regression

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The following table shows part of the probability distribution for the number of boats sold daily at Boats Unlimited. It is known that the average number of boats sold daily is 1.57. Compute the variance and the standard deviation for this probability distribution.

Consider the probability distribution below. The expected value of x equals

Roth is a computer-consulting firm. The number of new clients that they have obtained each month has ranged from 0 to 6. The number of new clients has the probability distribution that is shown below. The expected number of new clients per month is

Consider the probability distribution below. The variance of x equals

Roth is a computer-consulting firm. The number of new clients that they have obtained each month has ranged from 0 to 6. The number of new clients has the probability distribution that is shown below. The variance is

The binomial probability distribution is most symmetric when

The number of electrical outages in a city varies from day to day. Assume that the number of electrical outages (x) in the city has the following probability distribution. The mean and the standard deviation for the number of electrical outages (respectively) are

A sample of 2,500 people was asked how many cups of coffee they drink in the morning. You are given the following sample information. The expected number of cups of coffee is