Question 1

A jar contains 10 red marbles and 30 blue marbles.What is the probability of randomly selecting a red marble from the jar?

Accepted Answer

A) 10/30 
B) 10/40 
C) 1/10 
D) 1/40 
A) 10/30 
B) 10/40 
C) 1/10 
D) 1/40 B

Question 2

For a binomial distribution, the probability of obtaining a score of X = 19 or greater is computed as p(X > 18.5).

Accepted Answer

A) True 
 B)False  True

Question 3

What z-score value separates the top 10% of a normal distribution from the bottom 90%?

Accepted Answer

A) z = 1.28 
B) z = 0.25 
C) z = -1.28 
D) z = -0.25 
A) z = 1.28 
B) z = 0.25 
C) z = -1.28 
D) z = -0.25 A

Question 4

What proportion of a normal distribution is located between the mean and z = -0.40?

Accepted Answer

A) 0.6554 
B) 0.3446 
C) 0.1554 
D) 0.3108 
A) 0.6554 
B) 0.3446 
C) 0.1554 
D) 0.3108

Question 5

John drives to work each morning and the trip takes an average of µ = 38 minutes.The distribution of driving times is approximately normal with a standard deviation of σ = 5 minutes.For a randomly selected morning, what is the probability that John's drive to work will take less than 35 minutes?

Accepted Answer

A) 0.6554 
B) 0.3446 
C) 0.7257 
D) 0.2743 
A) 0.6554 
B) 0.3446 
C) 0.7257 
D) 0.2743

Question 6

A vertical line is drawn through a normal distribution at z = 0.80.What proportion of the distribution is on the right-hand side of the line?

Accepted Answer

A) 0.7881 
B) 0.2119 
C) 0.2881 
D) 0.5762 
A) 0.7881 
B) 0.2119 
C) 0.2881 
D) 0.5762

Question 7

What is the probability of randomly selecting a z-score greater than z = 0.75 from a normal distribution.

Accepted Answer

A) 0.7734 
B) 0.2266 
C) 0.2734 
D) 0.4532 
A) 0.7734 
B) 0.2266 
C) 0.2734 
D) 0.4532

Question 8

A vertical line is drawn through a normal distribution at z = 0.50, and separates the distribution into two sections.What proportion of the distribution is in the larger section?

Accepted Answer

A) 0.6915 
B) 0.3085 
C) 0.1915 
D) 0.3830 
A) 0.6915 
B) 0.3085 
C) 0.1915 
D) 0.3830

Question 9

A normal distribution has a mean of µ = 70 with σ = 12.If one score is randomly selected from this distribution, what is the probability that the score will be greater than X = 58?

Accepted Answer

A) 0.8413 
B) 0.1577 
C) 0.3413 
D) 0.6826 
A) 0.8413 
B) 0.1577 
C) 0.3413 
D) 0.6826

Question 10

When the z-score value in a normal distribution is negative, the body is on the right-hand side of the distribution.

Accepted Answer

A) True 
 B)False

Question 11

John drives to work each morning and the trip takes an average of µ = 38 minutes.The distribution of driving times is approximately normal with a standard deviation of σ = 5 minutes.For a randomly selected morning, what is the probability that John's drive to work will take between 36 and 40 minutes?

Accepted Answer

A) 0.0793 
B) 0.1526 
C) 0.1554 
D) 0.3108 
A) 0.0793 
B) 0.1526 
C) 0.1554 
D) 0.3108

Question 12

Which of the following are requirements of a random sample?

Accepted Answer

A) every individual has an equal chance of being selected 
B) the probabilities cannot change during a series of selections 
C) there must be sampling with replacement 
D) All of the other 3 choices are correct. 
A) every individual has an equal chance of being selected 
B) the probabilities cannot change during a series of selections 
C) there must be sampling with replacement 
D) All of the other 3 choices are correct.

Question 13

For a normal distribution with µ = 100 and σ = 20, the score that separates the top 60% of the distribution from the bottom 40% is X = 95.

Accepted Answer

A) True 
 B)False

Question 14

What z-score values form the boundaries for the middle 60% of a normal distribution?

Accepted Answer

A) z = +0.25 and z = -0.25 
B) z = +0.39 and z = -0.39 
C) z = +0.52 and z = -0.52 
D) z = +0.84 and z = -0.84 
A) z = +0.25 and z = -0.25 
B) z = +0.39 and z = -0.39 
C) z = +0.52 and z = -0.52 
D) z = +0.84 and z = -0.84

Question 15

A binomial distribution has p = 1/5 and q = 4/5 with n = 100.In the normal approximation to this distribution what is the z -score corresponding to X = 25?

Accepted Answer

A) z = 0.50 
B) z = 1.00 
C) z = 1.25 
D) z = 1.50 
A) z = 0.50 
B) z = 1.00 
C) z = 1.25 
D) z = 1.50

Question 16

A multiple-choice test with 48 questions has four choices for each question.What is the probability of getting more than 12 questions correct by just guessing?

Accepted Answer

A) 0.5000 
B) 0.4325 
C) 0.5675 
D) 0.0675 
A) 0.5000 
B) 0.4325 
C) 0.5675 
D) 0.0675

Question 17

A normal distribution has μ = 80 and σ = 10.What is the probability of randomly selecting a score greater than 90 from this distribution?

Accepted Answer

A) p = 0.8413 
B) p = 0.1587 
C) p = 0.3085 
D) p = 0.6915 
A) p = 0.8413 
B) p = 0.1587 
C) p = 0.3085 
D) p = 0.6915

Question 18

For any normal distribution, the proportion in the tail beyond z = 2.00 is p = 0.0228.

Accepted Answer

A) True 
 B)False

Question 19

What is the probability of randomly selecting a z-score less than z = 1.25 from a normal distribution.

Accepted Answer

A) 0.8944 
B) 0.1056 
C) 0.3944 
D) 0.2112 
A) 0.8944 
B) 0.1056 
C) 0.3944 
D) 0.2112

Question 20

A normal distribution has a mean of µ = 80 with σ = 20.What score separates the highest 15% of the distribution from the rest of the scores?

Accepted Answer

A) X = 59.2 
B) X = 100.8 
C) X = 95 
D) X = 65 
A) X = 59.2 
B) X = 100.8 
C) X = 95 
D) X = 65

A jar contains 10 red marbles and 30 blue marbles.What is the probability of randomly selecting a red marble from the jar?

For a binomial distribution, the probability of obtaining a score of X = 19 or greater is computed as p(X > 18.5).

What z-score value separates the top 10% of a normal distribution from the bottom 90%?

What proportion of a normal distribution is located between the mean and z = -0.40?

John drives to work each morning and the trip takes an average of µ = 38 minutes.The distribution of driving times is approximately normal with a standard deviation of σ = 5 minutes.For a randomly selected morning, what is the probability that John's drive to work will take less than 35 minutes?

A vertical line is drawn through a normal distribution at z = 0.80.What proportion of the distribution is on the right-hand side of the line?

What is the probability of randomly selecting a z-score greater than z = 0.75 from a normal distribution.

A vertical line is drawn through a normal distribution at z = 0.50, and separates the distribution into two sections.What proportion of the distribution is in the larger section?

A normal distribution has a mean of µ = 70 with σ = 12.If one score is randomly selected from this distribution, what is the probability that the score will be greater than X = 58?

When the z-score value in a normal distribution is negative, the body is on the right-hand side of the distribution.

Which of the following are requirements of a random sample?

For a normal distribution with µ = 100 and σ = 20, the score that separates the top 60% of the distribution from the bottom 40% is X = 95.

What z-score values form the boundaries for the middle 60% of a normal distribution?

A binomial distribution has p = 1/5 and q = 4/5 with n = 100.In the normal approximation to this distribution what is the z -score corresponding to X = 25?

A multiple-choice test with 48 questions has four choices for each question.What is the probability of getting more than 12 questions correct by just guessing?

A normal distribution has μ = 80 and σ = 10.What is the probability of randomly selecting a score greater than 90 from this distribution?

For any normal distribution, the proportion in the tail beyond z = 2.00 is p = 0.0228.

What is the probability of randomly selecting a z-score less than z = 1.25 from a normal distribution.

A normal distribution has a mean of µ = 80 with σ = 20.What score separates the highest 15% of the distribution from the rest of the scores?

Introduction to Statistics

Frequency Distributions

Central Tendency

Variability

Z-Scores

The Distribution of Sample Means

Introduction to Hypothesis Testing

Introduction to the T Statistic

The T Test for Two Independent Samples

The T Test for Two Related Samples

Introduction to Analysis of Variance

Repeated-Measures Anova

Two-Factor Analysis of Variance

Correlation

Introduction to Regression

Chi-Square Tests

The Binomial Test

Choosing the Right Statistics

Filters

Exam 6: Probability

A jar contains 10 red marbles and 30 blue marbles.What is the probability of randomly selecting a red marble from the jar?

For a binomial distribution, the probability of obtaining a score of X = 19 or greater is computed as p(X > 18.5).

What z-score value separates the top 10% of a normal distribution from the bottom 90%?

What proportion of a normal distribution is located between the mean and z = -0.40?

John drives to work each morning and the trip takes an average of µ = 38 minutes.The distribution of driving times is approximately normal with a standard deviation of σ = 5 minutes.For a randomly selected morning, what is the probability that John's drive to work will take less than 35 minutes?

A vertical line is drawn through a normal distribution at z = 0.80.What proportion of the distribution is on the right-hand side of the line?

What is the probability of randomly selecting a z-score greater than z = 0.75 from a normal distribution.

A vertical line is drawn through a normal distribution at z = 0.50, and separates the distribution into two sections.What proportion of the distribution is in the larger section?

A normal distribution has a mean of µ = 70 with σ = 12.If one score is randomly selected from this distribution, what is the probability that the score will be greater than X = 58?

When the z-score value in a normal distribution is negative, the body is on the right-hand side of the distribution.

Which of the following are requirements of a random sample?

For a normal distribution with µ = 100 and σ = 20, the score that separates the top 60% of the distribution from the bottom 40% is X = 95.

What z-score values form the boundaries for the middle 60% of a normal distribution?

A binomial distribution has p = 1/5 and q = 4/5 with n = 100.In the normal approximation to this distribution what is the z -score corresponding to X = 25?

A multiple-choice test with 48 questions has four choices for each question.What is the probability of getting more than 12 questions correct by just guessing?

A normal distribution has μ = 80 and σ = 10.What is the probability of randomly selecting a score greater than 90 from this distribution?

For any normal distribution, the proportion in the tail beyond z = 2.00 is p = 0.0228.

What is the probability of randomly selecting a z-score less than z = 1.25 from a normal distribution.

A normal distribution has a mean of µ = 80 with σ = 20.What score separates the highest 15% of the distribution from the rest of the scores?

Introduction to Statistics

Frequency Distributions

Central Tendency

Variability

Z-Scores

The Distribution of Sample Means

Introduction to Hypothesis Testing

Introduction to the T Statistic

The T Test for Two Independent Samples

The T Test for Two Related Samples

Introduction to Analysis of Variance

Repeated-Measures Anova

Two-Factor Analysis of Variance

Correlation

Introduction to Regression

Chi-Square Tests

The Binomial Test

Choosing the Right Statistics

Filters