We are open Saturday and Sunday!

Call Now to Set Up Tutoring:

(888) 888-0446

GRE Subject Test: Math : Z-Distribution

Study concepts, example questions & explanations for GRE Subject Test: Math

Create An Account

All GRE Subject Test: Math Resources

2 Diagnostic Tests 148 Practice Tests Question of the Day Flashcards Learn by Concept

Example Questions

Example Question #1 : How To Find Z Scores For A Data Set

The average score on the statistics final exam was 85 and the standard deviation was 2.5 . Chris scored a . Chris scored higher than what percent of his class?

Possible Answers:

95.7

Correct answer:

Explanation:

The first step in this problem is calculating the z-score. $z=( x-\mu)/\sigma$

(95-85)/2.5= 4

The next step is to look up 4 in the z-table. The value from the table is .

$1-.0000317\: is \: .9999683.$

Report an Error

Example Question #1 : How To Find Z Scores For A Data Set

What is the -score for a value of 115 when the mean of the population is 103 and the standard deviation is 8?

Possible Answers:

1.7

2.3

14.37

1.5

Correct answer:

1.5

Explanation:

A -score indicates whether a particular value is typical for a population or data set. The closer the -score is to 0, the closer the value is to the mean of the population and the more typical it is. The -score is calculated by subtracting the mean of a population from the particular value in question, then dividing the result by the population's standard deviation.

$z=\frac{X-\bar{X}}S{}$

(115-103)/8=1.5

Report an Error

Example Question #1 : How To Find Z Scores For A Data Set

A population of values has a mean of 43 and a standard deviation of 12. One of the values in the population is 49. What is the Z-score for that value?

Possible Answers:

0.5

0.8

-0.8

0.05

Correct answer:

0.5

Explanation:

A Z-score indicates whether a particular value is typical for a population or data set. The closer the Z-score is to 0, the closer the value is to the mean of the population and the more typical it is. The Z-score is calculated by subtracting the mean of a population from the particular value in question, then dividing the result by the population's standard deviation.

Report an Error

Example Question #2 : How To Find Z Scores For A Data Set

The z-score is also known as the standard score.

The average temperature for all the days preceding the last for the month of February was 55 degrees Farhenheit, with a standard deviation of 5 degrees.

On the last day, the temperature was 73 degrees F. What is the z-score for the temperature on the last day?

Possible Answers:

1.7

3.6

-3.6

2.8

Correct answer:

3.6

Explanation:

To find the z-score, follow the formula

$z=\frac{x-\mu}{\sigma }, x=score, \mu=mean, \sigma=S.D.$

$z=\frac{73-55}{5}$

z=3.6

Report an Error

Example Question #3 : How To Find Z Scores For A Data Set

A population has a standard deviation of 3.5 and a mean of 17.2 . One of the values in the population is 19.5 . What is the z score for that value?

Possible Answers:

-0.6

-14.3

1.3

14.6

0.66

Correct answer:

0.66

Explanation:

A z score is unique to each value within a population.

To find a z score, subtract the mean of a population from the particular value in question, then divide the result by the population's standard deviation.

$z=\frac{x-\mu}{\sigma}=\frac{19.5-17.2}{3.5}= \frac{2.3}{3.5}=0.6571$

Report an Error

Example Question #1 : How To Find Z Scores For A Data Set

Natalie took her university placement examinations in Spanish and math. In Spanish, she scored 82; in math, she scored 86. The results of the Spanish exam had a mean of 72 and a standard deviation of 8. The results of the math exam had a mean of 68 and a standard deviation of 12. On which exam did Natalie do better, compared with the rest of her peers taking these placement exams?

Possible Answers:

The Spanish exam

The Math exam

She did equally well on both exams

None of the other answers, as z-scores cannot be calculated for this question

Correct answer:

The Math exam

Explanation:

We need to calculate Natalie's z-scores for both her Spanish and math exams. Calculating z-scores is as follows:

$\small z=\frac{x-\bar{x}}{s}$

Her z-score for the Spanish exam is $\small \frac{82-72}{8}$ , which equals 1.25, while her z-score for the math exam is $\small \frac{86-68}{12}$ , which equals 1.50. Since both z-scores are positive, Natalie did above average on both tests, but since her z-score for the math exam is higher than her z-score for the Spanish exam, Natalie did better on her math exam when compared to the rest of her peers taking the exam.

Report an Error

Example Question #4 : How To Find Z Scores For A Data Set

This year's harvest, the apples had a mean mass of 102g with a standard deviation of . You pick an apple from the harvest and find its mass to be 111g .

What is the z-score of the apple you picked?

Possible Answers:

0.4

1.5

Correct answer:

Explanation:

To find the z-score, we follow the formula

$z=\frac{x-\mu }{\sigma }$ where is the given value, $\mu$ is the mean, and $\sigma$ is the standard deviation.

For this problem we see that

x=111

$\mu = 102$ and

$\sigma =9$

Substituting for these values we see

$z=\frac{111-102 }{9 } =1$

Report an Error

Example Question #112 : Other Topics

A bread maker has an average life of 9 years, with a variance of 4 years. What is the z-score associated with the probability that a bread maker lasts less than 13 years?

Possible Answers:

Correct answer:

Explanation:

$z=\frac{X-\mu }{\sigma }$

$\mu$ is the average life of the bread maker, in this problem 9 years.

$\sigma$ is the standard deviation of the break makers life. The standard deviation is the square root of the variance.

$\sigma=\sqrt{4}=2$

X is the test statistic we are looking to find. In this problem it is the probability that the bread maker lasts less than 13 years.

$z=\frac{13-9 }{2}=\frac{4}{2}=2$

If you were to find the value associated with a z-score of 2 on the z-table, you would see that

$Pr(X\leq 13)=.9973$

Report an Error

View Tutors

Abdul Azeez
Certified Tutor

University of Manitoba, Master's/Graduate, Business.

View Tutors

Evgenii
Certified Tutor

View Tutors

Omar
Certified Tutor

Arizona State University, Bachelors, Civil Engineering.

All GRE Subject Test: Math Resources

2 Diagnostic Tests 148 Practice Tests Question of the Day Flashcards Learn by Concept

Popular Subjects

Reading Tutors in Seattle, Math Tutors in Washington DC, MCAT Tutors in Phoenix, Algebra Tutors in Boston, GMAT Tutors in Dallas Fort Worth, ISEE Tutors in Phoenix, GRE Tutors in Seattle, SAT Tutors in Boston, Calculus Tutors in New York City, SSAT Tutors in Los Angeles

Popular Courses & Classes

ISEE Courses & Classes in Denver, LSAT Courses & Classes in Seattle, Spanish Courses & Classes in Miami, SAT Courses & Classes in Miami, SSAT Courses & Classes in San Diego, LSAT Courses & Classes in San Francisco-Bay Area, SSAT Courses & Classes in New York City, ACT Courses & Classes in Houston, Spanish Courses & Classes in New York City, SSAT Courses & Classes in Phoenix

Popular Test Prep

GRE Test Prep in Philadelphia, LSAT Test Prep in Boston, GMAT Test Prep in Boston, GRE Test Prep in San Diego, ISEE Test Prep in Dallas Fort Worth, ISEE Test Prep in Chicago, LSAT Test Prep in Miami, SAT Test Prep in Chicago, LSAT Test Prep in New York City, MCAT Test Prep in Atlanta

DMCA Complaint

If you believe that content available by means of the Website (as defined in our Terms of Service) infringes one or more of your copyrights, please notify us by providing a written notice (“Infringement Notice”) containing the information described below to the designated agent listed below. If Varsity Tutors takes action in response to an Infringement Notice, it will make a good faith attempt to contact the party that made such content available by means of the most recent email address, if any, provided by such party to Varsity Tutors.

Your Infringement Notice may be forwarded to the party that made the content available or to third parties such as ChillingEffects.org.

Please be advised that you will be liable for damages (including costs and attorneys’ fees) if you materially misrepresent that a product or activity is infringing your copyrights. Thus, if you are not sure content located on or linked-to by the Website infringes your copyright, you should consider first contacting an attorney.

Please follow these steps to file a notice:

You must include the following:

A physical or electronic signature of the copyright owner or a person authorized to act on their behalf; An identification of the copyright claimed to have been infringed; A description of the nature and exact location of the content that you claim to infringe your copyright, in \ sufficient detail to permit Varsity Tutors to find and positively identify that content; for example we require a link to the specific question (not just the name of the question) that contains the content and a description of which specific portion of the question – an image, a link, the text, etc – your complaint refers to; Your name, address, telephone number and email address; and A statement by you: (a) that you believe in good faith that the use of the content that you claim to infringe your copyright is not authorized by law, or by the copyright owner or such owner’s agent; (b) that all of the information contained in your Infringement Notice is accurate, and (c) under penalty of perjury, that you are either the copyright owner or a person authorized to act on their behalf.

Send your complaint to our designated agent at:

Charles Cohn Varsity Tutors LLC
101 S. Hanley Rd, Suite 300
St. Louis, MO 63105

Or fill out the form below:

Do not fill in this field

Contact Information

* Full legal name

Company name

* Phone number

* Email address

Address

* Address1

Address2

* City

* State

* Zipcode

* Country

Complaint Details

* URL of copyrighted work (where your original material is located)

* Please describe the copyrighted work so that it may be easily identified

I am the owner, or an agent authorized to act on behalf of the owner of an exclusive right that is allegedly infringed.

I have a good faith belief that the use of the material in the manner complained of is not authorized by the copyright owner, its agent, or the law.

This notification is accurate.

I acknowledge that there may be adverse legal consequences for making false or bad faith allegations of copyright infringement by using this process.

* Signature (your digital signature is legally binding)

HIGH SCHOOL

GRADUATE SCHOOL

K-8

Search 50+ Tests

math tutoring

science tutoring

foreign languages

elementary tutoring

other

Search 350+ Subjects

GRE Subject Test: Math : Z-Distribution

Study concepts, example questions & explanations for GRE Subject Test: Math

All GRE Subject Test: Math Resources

Example Questions

Example Question #1 : How To Find Z Scores For A Data Set

Example Question #1 : How To Find Z Scores For A Data Set

Example Question #1 : How To Find Z Scores For A Data Set

Example Question #2 : How To Find Z Scores For A Data Set

Example Question #3 : How To Find Z Scores For A Data Set

Example Question #1 : How To Find Z Scores For A Data Set

Example Question #4 : How To Find Z Scores For A Data Set

Example Question #112 : Other Topics

All GRE Subject Test: Math Resources

Report an issue with this question

DMCA Complaint

Contact Information

Address

Complaint Details

Email address:
Your name:
Feedback: