Question 1

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 D

Question 2

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 B

Question 3

The middle 90% of a normal distribution is located between z = -1.96 and z = 1.96

Accepted Answer

A) True 
 B)False  False

Question 4

Which of the following is a requirement for 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 5

For any normal distribution,exactly 97.50% of the z-score values are less than z = 1.96.

Accepted Answer

A) True 
 B)False

Question 6

For a normal distribution with a mean of µ = 100 and a standard deviation of σ = 10,find each of the following probabilities:
a.p(X > 102)
b.p(X < 85)
c.p(X < 130)
d.p(95 < X < 105)

Accepted Answer

a.z = 0.20 p = 0.420

Question 7

A class consists of 10 male and 30 female students.If one student is randomly selected from the class,what is the probability of selecting a male student?

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

Question 8

IQ scores form a normal distribution with µ = 100 and σ = 15.Individuals with IQs above 140 are classified in the genius category.What proportion of the population consists of geniuses?

Accepted Answer

A) 0.9962 
B) 0.5038 
C) 0.4962 
D) 0.0038 
A) 0.9962 
B) 0.5038 
C) 0.4962 
D) 0.0038

Question 9

The probability of randomly selecting a red marble from a jar that contains 10 red marbles and 20 blue marbles is 1/30.

Accepted Answer

A) True 
 B)False

Question 10

For a normal distribution,
a.What z-score separates the highest 25% from the rest of the scores?
b.What z-score separates the highest 60% from the rest of the scores?
c.What z-score separates the lowest 30% from the rest of the scores?
d.What z-score separates the lowest 80% from the rest of the scores?

Accepted Answer

a.z = 0.67

Question 11

For a population with a mean of μ = 80 and σ = 10,only 2.28% of the scores are greater than X = 100.

Accepted Answer

A) True 
 B)False

Question 12

A vertical line is drawn through a normal distribution so that 47.5% of the distribution is located between the line and the mean.The line is drawn at z = 1.96 or at z = -1.96.

Accepted Answer

A) True 
 B)False

Question 13

For each of the following z-score locations in a normal distribution,determine whether the tail is on the left side or the right side of the distribution and find the proportion that is located in the tail.
a.z = +1.75
b.z = +0.80
c.z = -0.70
d.z = -1.65

Accepted Answer

a.Right 0.0401
b.Rig

Question 14

For a normal distribution,the proportion in the tail beyond z = -2.00 is equal to -0.0228.

Accepted Answer

A) True 
 B)False

Question 15

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 = 90 and X = 110?

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 16

A normal distribution has a mean of µ = 80 with σ = 20.What score separates the lowest 30% of the distribution from the rest of the scores?

Accepted Answer

A) X = 90.4 
B) X = 69.6 
C) X = 110 
D) X = 50 
A) X = 90.4 
B) X = 69.6 
C) X = 110 
D) X = 50

Question 17

What proportion of a normal distribution is located between the mean and z = 1.40?

Accepted Answer

A) 0.9192 
B) 0.0808 
C) 0.4192 
D) 0.8384 
A) 0.9192 
B) 0.0808 
C) 0.4192 
D) 0.8384

Question 18

What proportion of a normal distribution is located between z = -1.25 and z = +1.25?

Accepted Answer

A) 0.8944 
B) 0.2112 
C) 0.3944 
D) 0.7888 
A) 0.8944 
B) 0.2112 
C) 0.3944 
D) 0.7888

Question 19

A normal distribution has a mean of µ = 80 with σ = 20.What score separates the highest 40% of the distribution from the rest of the scores?

Accepted Answer

A) X = 75 
B) X = 85 
C) X = 54.4 
D) X = 105.6 
A) X = 75 
B) X = 85 
C) X = 54.4 
D) X = 105.6

Question 20

If one score is randomly selected from a normal distribution with µ = 100 and σ = 20,the probability of obtaining a score between X = 80 and X = 120 is p = 0.3413.

Accepted Answer

A) True 
 B)False

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

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

The middle 90% of a normal distribution is located between z = -1.96 and z = 1.96

Which of the following is a requirement for a random sample?

For any normal distribution,exactly 97.50% of the z-score values are less than z = 1.96.

For a normal distribution with a mean of µ = 100 and a standard deviation of σ = 10,find each of the following probabilities: a.p(X > 102) b.p(X < 85) c.p(X < 130) d.p(95 < X < 105)

A class consists of 10 male and 30 female students.If one student is randomly selected from the class,what is the probability of selecting a male student?

IQ scores form a normal distribution with µ = 100 and σ = 15.Individuals with IQs above 140 are classified in the genius category.What proportion of the population consists of geniuses?

The probability of randomly selecting a red marble from a jar that contains 10 red marbles and 20 blue marbles is 1/30.

For a population with a mean of μ = 80 and σ = 10,only 2.28% of the scores are greater than X = 100.

A vertical line is drawn through a normal distribution so that 47.5% of the distribution is located between the line and the mean.The line is drawn at z = 1.96 or at z = -1.96.

For each of the following z-score locations in a normal distribution,determine whether the tail is on the left side or the right side of the distribution and find the proportion that is located in the tail. a.z = +1.75 b.z = +0.80 c.z = -0.70 d.z = -1.65

For a normal distribution,the proportion in the tail beyond z = -2.00 is equal to -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 = 90 and X = 110?

A normal distribution has a mean of µ = 80 with σ = 20.What score separates the lowest 30% of the distribution from the rest of the scores?

What proportion of a normal distribution is located between the mean and z = 1.40?

What proportion of a normal distribution is located between z = -1.25 and z = +1.25?

A normal distribution has a mean of µ = 80 with σ = 20.What score separates the highest 40% of the distribution from the rest of the scores?

If one score is randomly selected from a normal distribution with µ = 100 and σ = 20,the probability of obtaining a score between X = 80 and X = 120 is p = 0.3413.

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 and Two-Factor Analysis of Variance

Correlation and Regression.

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

Filters

Exam 6: Probability.

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

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

The middle 90% of a normal distribution is located between z = -1.96 and z = 1.96

Which of the following is a requirement for a random sample?

For any normal distribution,exactly 97.50% of the z-score values are less than z = 1.96.

For a normal distribution with a mean of µ = 100 and a standard deviation of σ = 10,find each of the following probabilities: a.p(X > 102) b.p(X < 85) c.p(X < 130) d.p(95 < X < 105)

A class consists of 10 male and 30 female students.If one student is randomly selected from the class,what is the probability of selecting a male student?

IQ scores form a normal distribution with µ = 100 and σ = 15.Individuals with IQs above 140 are classified in the genius category.What proportion of the population consists of geniuses?

The probability of randomly selecting a red marble from a jar that contains 10 red marbles and 20 blue marbles is 1/30.

For a population with a mean of μ = 80 and σ = 10,only 2.28% of the scores are greater than X = 100.

A vertical line is drawn through a normal distribution so that 47.5% of the distribution is located between the line and the mean.The line is drawn at z = 1.96 or at z = -1.96.

For each of the following z-score locations in a normal distribution,determine whether the tail is on the left side or the right side of the distribution and find the proportion that is located in the tail. a.z = +1.75 b.z = +0.80 c.z = -0.70 d.z = -1.65

For a normal distribution,the proportion in the tail beyond z = -2.00 is equal to -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 = 90 and X = 110?

A normal distribution has a mean of µ = 80 with σ = 20.What score separates the lowest 30% of the distribution from the rest of the scores?

What proportion of a normal distribution is located between the mean and z = 1.40?

What proportion of a normal distribution is located between z = -1.25 and z = +1.25?

A normal distribution has a mean of µ = 80 with σ = 20.What score separates the highest 40% of the distribution from the rest of the scores?

If one score is randomly selected from a normal distribution with µ = 100 and σ = 20,the probability of obtaining a score between X = 80 and X = 120 is p = 0.3413.

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 and Two-Factor Analysis of Variance

Correlation and Regression.

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

Filters