Question 1

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 2

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 less than X = 76?​

Accepted Answer

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

Question 3

A true/false test has 100 questions.Using the normal approximation to the binomial distribution,what is the probability of getting 55 or more correct by just guessing?​

Accepted Answer

A) ​p(X > 55) 
B) ​p(X > 55.5) 
C) ​p(X > 54.5) 
D) ​p(X > 45) 
A) ​p(X > 55) 
B) ​p(X > 55.5) 
C) ​p(X > 54.5) 
D) ​p(X > 45)

Question 4

A normal distribution has a mean of µ = 100 with σ = 20.Find the following probabilities:
a. p(X > 102)
b. p(X < 65)
c. p(X < 130)
d. p(95 < X < 105)

Accepted Answer

a.z = 0.10,p = 0.460

Question 5

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

Question 6

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 7

For a normal distribution,
a. What z-score separates the highest 10% from the rest of the scores?
b. What z-score separates the highest 30% from the rest of the scores?
c. What z-score separates the lowest 40% from the rest of the scores?
d. What z-score separates the lowest 20% from the rest of the scores?

Accepted Answer

a.z = 1.28

Question 8

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 9

For a binomial distribution with p = q = 1/2 and n = 36,what is the mean for the normal approximation?​

Accepted Answer

A) ​3 
B) ​9 
C) ​16 
D) ​18 
A) ​3 
B) ​9 
C) ​16 
D) ​18

Question 10

For a normal distribution,the proportion in the tail beyond z = 1.50 is p = 0.0668.

Accepted Answer

A) True 
 B)False

Question 11

A vertical line is drawn through a normal distribution dividing the distribution into two parts.If the smaller part equals 0.1915 of the distribution,then the line was drawn at z = 0.50 or at z = -0.50.

Accepted Answer

A) True 
 B)False

Question 12

A jar contains 10 red marbles and 30 blue marbles.A random sample without replacement of n = 3 marbles is selected from the jar.If the first two marbles are both blue,what is the probability that the third marble will be red?​

Accepted Answer

A) ​10/37 
B) ​10/38 
C) ​10/40 
D) ​8/38 
A) ​10/37 
B) ​10/38 
C) ​10/40 
D) ​8/38

Question 13

What proportion of a normal distribution is located in the tail beyond z = -1.00?​

Accepted Answer

A) ​0.8413 
B) ​0.1587 
C) ​-0.3413 
D) ​-0.1587 
A) ​0.8413 
B) ​0.1587 
C) ​-0.3413 
D) ​-0.1587

Question 14

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

Accepted Answer

A) True 
 B)False

Question 15

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

Accepted Answer

A) True 
 B)False

Question 16

A normal distribution has a mean of µ = 100 with σ = 20.If one score is randomly selected from this distribution,what is the probability that the score will have a value between X = 80 and X = 100?​

Accepted Answer

A) ​0.8413 
B) ​0.1587 
C) ​0.3413 
D) ​0.6826 
A) ​0.8413 
B) ​0.1587 
C) ​0.3413 
D) ​0.6826

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 = 70 with σ = 12.If one score is randomly selected from this distribution,what is the probability that the score will be less than X = 76?

A true/false test has 100 questions.Using the normal approximation to the binomial distribution,what is the probability of getting 55 or more correct by just guessing?

A normal distribution has a mean of µ = 100 with σ = 20.Find the following probabilities: a. p(X > 102) b. p(X < 65) c. p(X < 130) d. p(95 < X < 105)

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 values form the boundaries for the middle 60% of a normal distribution?

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?

For a binomial distribution with p = q = 1/2 and n = 36,what is the mean for the normal approximation?

For a normal distribution,the proportion in the tail beyond z = 1.50 is p = 0.0668.

A vertical line is drawn through a normal distribution dividing the distribution into two parts.If the smaller part equals 0.1915 of the distribution,then the line was drawn at z = 0.50 or at z = -0.50.

A jar contains 10 red marbles and 30 blue marbles.A random sample without replacement of n = 3 marbles is selected from the jar.If the first two marbles are both blue,what is the probability that the third marble will be red?

What proportion of a normal distribution is located in the tail beyond z = -1.00?

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

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

A normal distribution has a mean of µ = 100 with σ = 20.If one score is randomly selected from this distribution,what is the probability that the score will have a value between X = 80 and X = 100?

Introduction to Statistics

Frequency Distributions

Central Tendency

Variability

Z-Scores: Location of Scores and Standardized Distributions

Probability and Samples: 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 Analysis of Variance Anova

Two-Factor Analysis of Variance Independent Measures

Correlation

Introduction to Regression

The Chi-Square Statistic: Tests for Goodness of Fit and Independence

The Binomial Test

Filters

Exam 6: Probability

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 = 70 with σ = 12.If one score is randomly selected from this distribution,what is the probability that the score will be less than X = 76?​

A true/false test has 100 questions.Using the normal approximation to the binomial distribution,what is the probability of getting 55 or more correct by just guessing?​

A normal distribution has a mean of µ = 100 with σ = 20.Find the following probabilities: a. p(X > 102) b. p(X < 65) c. p(X < 130) d. p(95 < X < 105)

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 values form the boundaries for the middle 60% of a normal distribution?​

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?​

For a binomial distribution with p = q = 1/2 and n = 36,what is the mean for the normal approximation?​

For a normal distribution,the proportion in the tail beyond z = 1.50 is p = 0.0668.

A vertical line is drawn through a normal distribution dividing the distribution into two parts.If the smaller part equals 0.1915 of the distribution,then the line was drawn at z = 0.50 or at z = -0.50.

A jar contains 10 red marbles and 30 blue marbles.A random sample without replacement of n = 3 marbles is selected from the jar.If the first two marbles are both blue,what is the probability that the third marble will be red?​

What proportion of a normal distribution is located in the tail beyond z = -1.00?​

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

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

A normal distribution has a mean of µ = 100 with σ = 20.If one score is randomly selected from this distribution,what is the probability that the score will have a value between X = 80 and X = 100?​

Introduction to Statistics

Frequency Distributions

Central Tendency

Variability

Z-Scores: Location of Scores and Standardized Distributions

Probability and Samples: 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 Analysis of Variance Anova

Two-Factor Analysis of Variance Independent Measures

Correlation

Introduction to Regression

The Chi-Square Statistic: Tests for Goodness of Fit and Independence

The Binomial Test

Filters

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 = 70 with σ = 12.If one score is randomly selected from this distribution,what is the probability that the score will be less than X = 76?

A true/false test has 100 questions.Using the normal approximation to the binomial distribution,what is the probability of getting 55 or more correct by just guessing?

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 values form the boundaries for the middle 60% of a normal distribution?

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?

For a binomial distribution with p = q = 1/2 and n = 36,what is the mean for the normal approximation?

A jar contains 10 red marbles and 30 blue marbles.A random sample without replacement of n = 3 marbles is selected from the jar.If the first two marbles are both blue,what is the probability that the third marble will be red?

What proportion of a normal distribution is located in the tail beyond z = -1.00?

A normal distribution has a mean of µ = 100 with σ = 20.If one score is randomly selected from this distribution,what is the probability that the score will have a value between X = 80 and X = 100?