Question 1

Which of the following is not a requirement of a binomial distribution?

Accepted Answer

A) Constant probability of success 
B) Only two possible Bernoulli outcomes 
C) Fixed number of trials 
D) Equally likely outcomes 
A) Constant probability of success 
B) Only two possible Bernoulli outcomes 
C) Fixed number of trials 
D) Equally likely outcomes D

Question 2

In Quebec, 90 percent of the population subscribes to the Roman Catholic religion. In a random sample of eight Quebecois, find the probability that the sample contains at least five Roman Catholics.

Accepted Answer

A) .0050 
B) .0331 
C) .9950 
D) .9619 
A) .0050 
B) .0331 
C) .9950 
D) .9619 C

Question 3

The domain of X in a Poisson probability distribution is discrete and can include:

Accepted Answer

A) any real X value. 
B) any integer X value. 
C) any nonnegative integer X value. 
D) any X value except zero. 
A) any real X value. 
B) any integer X value. 
C) any nonnegative integer X value. 
D) any X value except zero. C

Question 4

The random variable X is the number of shots it takes before you make the first free throw in basketball. Assuming the probability of success (making a free throw) is constant from trial to trial, what type of distribution does X follow?

Accepted Answer

A) Binomial 
B) Poisson 
C) Hypergeometric 
D) Geometric 
A) Binomial 
B) Poisson 
C) Hypergeometric 
D) Geometric

Question 5

The probability that a ticket holder will miss a flight is .005. If 180 passengers take the flight, what is the approximate Poisson probability that at least 2 will miss the flight?

Accepted Answer

A) .9372 
B) .0628 
C) .1647 
D) .2275 
A) .9372 
B) .0628 
C) .1647 
D) .2275

Question 6

The geometric distribution best describes:

Accepted Answer

A) the number of successes in a sample of n trials. 
B) the number of trials until the first success. 
C) the number of events in a given unit of time. 
D) the process of sampling without replacement. 
A) the number of successes in a sample of n trials. 
B) the number of trials until the first success. 
C) the number of events in a given unit of time. 
D) the process of sampling without replacement.

Question 7

Which is not a discrete random variable?

Accepted Answer

A) The number of defects in a 4 × 8 sheet of plywood 
B) The number of female passengers who board a plane 
C) The time until failure of a vehicle headlamp 
D) The number of correct answers on a statistics exam 
A) The number of defects in a 4 × 8 sheet of plywood 
B) The number of female passengers who board a plane 
C) The time until failure of a vehicle headlamp 
D) The number of correct answers on a statistics exam

Question 8

Ephemeral Services Corporation (ESCO) knows that nine other companies besides ESCO are bidding for a $900,000 government contract. Each company has an equal chance of being awarded the contract. If ESCO has already spent $100,000 in developing its bidding proposal, what is its expected net profit?

Accepted Answer

A) $100,000 
B) $90,000 
C) -$10,000 
D) $0 
A) $100,000 
B) $90,000 
C) -$10,000 
D) $0

Question 9

As a rule of thumb, the binomial distribution can be used to approximate the hypergeometric distribution whenever the population is at least 20 times as large as the sample.

Accepted Answer

A) True 
 B)False

Question 10

Which statement concerning the binomial distribution is correct?

Accepted Answer

A) Its PDF covers all integer values of X from 0 to n. 
B) Its PDF is the same as its CDF when π = .50. 
C) Its CDF shows the probability of each value of X. 
D) Its CDF is skewed right when π < .50. 
A) Its PDF covers all integer values of X from 0 to n. 
B) Its PDF is the same as its CDF when π = .50. 
C) Its CDF shows the probability of each value of X. 
D) Its CDF is skewed right when π < .50.

Question 11

Given the following probability distribution, what is the expected value of the random variable X? $$\begin{array} { c c } 
X & P ( X ) \
100 & .10 \
150 & .20 \
200 & .30 \
250 & .30 \
300 & .10 \
\text { Sum } & 1.00
\end{array}$$

Accepted Answer

A) 175 
B) 150 
C) 200 
D) 205 
A) 175 
B) 150 
C) 200 
D) 205

Question 12

On a randomly chosen Wednesday, which probability model would you use to describe the number of convenience store robberies in Los Angeles?

Accepted Answer

A) Binomial 
B) Poisson 
C) Hypergeometric 
D) Geometric 
A) Binomial 
B) Poisson 
C) Hypergeometric 
D) Geometric

Question 13

Which distribution has a mean of 5?

Accepted Answer

A) Poisson with λ = 25 
B) Binomial with n = 200, π = .05 
C) Hypergeometric with N = 100, n = 10, s = 50 
A) Poisson with λ = 25 
B) Binomial with n = 200, π = .05 
C) Hypergeometric with N = 100, n = 10, s = 50

Question 14

If the probability of success is .25, what is the probability of obtaining the first success within the first three trials?

Accepted Answer

A) .4218 
B) .5781 
C) .1406 
D) .2228 
A) .4218 
B) .5781 
C) .1406 
D) .2228

Question 15

A discrete random variable has a countable number of distinct values.

Accepted Answer

A) True 
 B)False

Question 16

On a particular Thursday in August, 40 Grand Canyon tourists enter a drawing for a free mule ride. Ten of the entrants are European tourists. Five entrants are selected at random to get the free mule ride. Which model best describes the number of European tourists in the random sample?

Accepted Answer

A) Binomial 
B) Poisson 
C) Hypergeometric 
D) Geometric 
A) Binomial 
B) Poisson 
C) Hypergeometric 
D) Geometric

Question 17

As a rule of thumb, the Poisson distribution can be used to approximate a binomial distribution when n ≥ 20 and π ≤ .05.

Accepted Answer

A) True 
 B)False

Question 18

The hypergeometric distribution is not applicable if sampling is done with replacement.

Accepted Answer

A) True 
 B)False

Question 19

The number of male babies in a sample of 10 randomly chosen babies is a:

Accepted Answer

A) continuous random variable. 
B) Poisson random variable. 
C) binary random variable. 
D) binomial random variable. 
A) continuous random variable. 
B) Poisson random variable. 
C) binary random variable. 
D) binomial random variable.

Question 20

Jankord Jewelers permits the return of their diamond wedding rings, provided the return occurs within two weeks. Typically, 10 percent are returned. If eight rings are sold today, what is the probability that fewer than three will be returned?

Accepted Answer

A) .9950 
B) .9619 
C) .0331 
D) .1488 
A) .9950 
B) .9619 
C) .0331 
D) .1488

Which of the following is not a requirement of a binomial distribution?

In Quebec, 90 percent of the population subscribes to the Roman Catholic religion. In a random sample of eight Quebecois, find the probability that the sample contains at least five Roman Catholics.

The domain of X in a Poisson probability distribution is discrete and can include:

The random variable X is the number of shots it takes before you make the first free throw in basketball. Assuming the probability of success (making a free throw) is constant from trial to trial, what type of distribution does X follow?

The probability that a ticket holder will miss a flight is .005. If 180 passengers take the flight, what is the approximate Poisson probability that at least 2 will miss the flight?

The geometric distribution best describes:

Which is not a discrete random variable?

Ephemeral Services Corporation (ESCO) knows that nine other companies besides ESCO are bidding for a $900,000 government contract. Each company has an equal chance of being awarded the contract. If ESCO has already spent $100,000 in developing its bidding proposal, what is its expected net profit?

As a rule of thumb, the binomial distribution can be used to approximate the hypergeometric distribution whenever the population is at least 20 times as large as the sample.

Which statement concerning the binomial distribution is correct?

Given the following probability distribution, what is the expected value of the random variable X? X P(X) 100 .10 150 .20 200 .30 250 .30 300 .10 Sum 1.00

On a randomly chosen Wednesday, which probability model would you use to describe the number of convenience store robberies in Los Angeles?

Which distribution has a mean of 5?

If the probability of success is .25, what is the probability of obtaining the first success within the first three trials?

A discrete random variable has a countable number of distinct values.

On a particular Thursday in August, 40 Grand Canyon tourists enter a drawing for a free mule ride. Ten of the entrants are European tourists. Five entrants are selected at random to get the free mule ride. Which model best describes the number of European tourists in the random sample?

As a rule of thumb, the Poisson distribution can be used to approximate a binomial distribution when n ≥ 20 and π ≤ .05.

The hypergeometric distribution is not applicable if sampling is done with replacement.

The number of male babies in a sample of 10 randomly chosen babies is a:

Jankord Jewelers permits the return of their diamond wedding rings, provided the return occurs within two weeks. Typically, 10 percent are returned. If eight rings are sold today, what is the probability that fewer than three will be returned?

Overview of Statistics

Data Collection

Describing Data Visually

Descriptive Statistics

Probability

Continuous Probability Distributions

Sampling Distributions and Estimation

One-Sample Hypothesis Tests

Two-Sample Hypothesis Tests

Analysis of Variance

Simple Regression

Multiple Regression

Time Series Analysis

Chi-Square Tests

Nonparametric Tests

Quality Management

Filters

Exam 6: Discrete Probability Distributions

Which of the following is not a requirement of a binomial distribution?

In Quebec, 90 percent of the population subscribes to the Roman Catholic religion. In a random sample of eight Quebecois, find the probability that the sample contains at least five Roman Catholics.

The domain of X in a Poisson probability distribution is discrete and can include:

The random variable X is the number of shots it takes before you make the first free throw in basketball. Assuming the probability of success (making a free throw) is constant from trial to trial, what type of distribution does X follow?

The probability that a ticket holder will miss a flight is .005. If 180 passengers take the flight, what is the approximate Poisson probability that at least 2 will miss the flight?

The geometric distribution best describes:

Which is not a discrete random variable?

Ephemeral Services Corporation (ESCO) knows that nine other companies besides ESCO are bidding for a $900,000 government contract. Each company has an equal chance of being awarded the contract. If ESCO has already spent $100,000 in developing its bidding proposal, what is its expected net profit?

As a rule of thumb, the binomial distribution can be used to approximate the hypergeometric distribution whenever the population is at least 20 times as large as the sample.

Which statement concerning the binomial distribution is correct?

Given the following probability distribution, what is the expected value of the random variable X? X P(X) 100 .10 150 .20 200 .30 250 .30 300 .10 Sum 1.00

On a randomly chosen Wednesday, which probability model would you use to describe the number of convenience store robberies in Los Angeles?

Which distribution has a mean of 5?

If the probability of success is .25, what is the probability of obtaining the first success within the first three trials?

A discrete random variable has a countable number of distinct values.

On a particular Thursday in August, 40 Grand Canyon tourists enter a drawing for a free mule ride. Ten of the entrants are European tourists. Five entrants are selected at random to get the free mule ride. Which model best describes the number of European tourists in the random sample?

As a rule of thumb, the Poisson distribution can be used to approximate a binomial distribution when n ≥ 20 and π ≤ .05.

The hypergeometric distribution is not applicable if sampling is done with replacement.

The number of male babies in a sample of 10 randomly chosen babies is a:

Jankord Jewelers permits the return of their diamond wedding rings, provided the return occurs within two weeks. Typically, 10 percent are returned. If eight rings are sold today, what is the probability that fewer than three will be returned?

Overview of Statistics

Data Collection

Describing Data Visually

Descriptive Statistics

Probability

Continuous Probability Distributions

Sampling Distributions and Estimation

One-Sample Hypothesis Tests

Two-Sample Hypothesis Tests

Analysis of Variance

Simple Regression

Multiple Regression

Time Series Analysis

Chi-Square Tests

Nonparametric Tests

Quality Management

Filters