## Assignment PSYCH 625 Statistics Practice

*Assignment: PSYCH 625 Statistics Practice *

Time to Practice Week Two

PSY 625

University of Phoenix Material

Time to Practice – Week Two

Complete Parts A, B, and C below.

**Part A**

Some questions in Part A require that you access data from Statistics for People Who (Think They) Hate Statistics. This data is available on the student website under the Student Text Resources link.

1. Why is a z score a standard score? Why can standard scores be used to compare scores from different distributions?

A z score is considered a standard score because it is based on the degree of variability within its distribution. Standard scores across different distributions measure in the same fashion. A z score is the result of dividing the amount that a raw score differs from the mean of the distribution by the standard deviation. So, scores below the mean will have negative z scores, and scores above the mean will have positive z scores. Positive z scores always fall to the right of the mean, and negative always fall to the left (Salkind, 2011).

2. For the following set of scores, fill in the cells. The mean is 70 and the standard deviation is 8.

Raw score

Z score

68.0

-0.25

57.2

–1.6

82.0

1.5

84.4

1.8

69.0

–0.125

66.0

–0.5

85.0

1.875

83.6

1.7

72.0

.25

3. Questions 3a through 3d are based on a distribution of scores with image2.png and the standard deviation = 6.38. Draw a small picture to help you see what is required. PSYCH/625 Statistics Practice Assignment

a. What is the probability of a score falling between a raw score of 70 and 80? 0.5668

b. What is the probability of a score falling above a raw score of 80? 0.2166

c. What is the probability of a score falling between a raw score of 81 and 83? 0.0686

d. What is the probability of a score falling below a raw score of 63? 0.0300

4. Jake needs to score in the top 10% in order to earn a physical fitness certificate. The class mean is 78 and the standard deviation is 5.5. What raw score does he need? (x-78) / 5.5 = .9 Minimum required score of 85.04

5. Who is the better student, relative to his or her classmates? Use the following table for information.

Math

Class mean

81

Class standard deviation

2

Reading

Class mean

87

Class standard deviation

10

Raw scores

Math score

Reading score

Average

Noah

85

88

86.5

Talya

87

81

84

Z-scores

Math score

Reading score

Average

Noah

2

0.1

1.05

Talya

3

-0.6

1.2

Talya is the better student.

From Salkind (2011). Copyright © 2012 SAGE. All Rights Reserved. Adapted with permission.

**Part B**

Some questions in Part B require that you access data from Using SPSS for Windows and Macintosh. This data is available on the student website under the Student Text Resources link.

The data for Exercises 6 and 7 are in the data file named Lesson 20 Exercise File 1. Answer Exercises 6 and 7 based on the following research problem:

Ann wants to describe the demographic characteristics of a sample of 25 individuals who completed a large-scale survey. She has demographic data on the participants’ gender (two categories), educational level (four categories), marital status (three categories), and community population size (eight categories).

6. Using IBM® SPSS® software, conduct a frequency analysis on the gender and marital status variables. From the output, identify the following:

a. Percent of men= 52%

b. Mode for marital status= 1

c. Frequency of divorced people in the sample= 11

7. Using IBM® SPSS® software, create a frequency table to summarize the data on the educational level variable.

Descriptive Statistics

N

Minimum

Maximum

Mean

Std. Deviation

Education Level

25

1

4

2.64

1.150

Valid N (listwise)

25

The data for Exercise 8 is available in the data file named Lesson 21 Exercise File 1.

8. David collects anxiety scores from 15 college students who visit the university health center during finals week. Compute descriptive statistics on the anxiety scores. From the output, identify the following:

a. Skewness=.416

b. Mean=32.27

c. Standard deviation=23.478

d. Kurtosis= -1.124 Standard error of Kurtosis = 1.121

From Green & Salkind (2011). Copyright © 2012 Pearson Education. All Rights Reserved. Adapted with permission.

**Part C**

Complete the questions below. Be specific and provide examples when relevant.

Cite any sources consistent with APA guidelines.

Question

Answer

What is the relationship between reliability and validity? How can a test be reliable but not valid? Can a test be valid but not reliable? Why or why not?

Reliability consists of test re-rest, parallel forms, internal consistency and interrater reliability (Salkind, 2011). For something to be reliable it must remain consistent. This goes for the measurements of the test results. For something to be considered reliable, the same conclusion must be met every time the formula is processed. PSYCH/625 Statistics Practice Assignment

Validity contains construct validity, internal validity, external validity and conclusion validity (Salkind, 2011). For something to be valid, it must remain true. So yes, something can be valid but the result may not appear every time exacts are performed so that would not make the formula valid but if something is valid, it performs as expected every time, which makes it reliable Salkind, 2011).

Statistics and probability are related. Probability is based off of statistics past events and looking at the outcomes of the probability of an action or decision reward being favorable to the action determines the probability of the individual’s decision. For example: Gambling at the casino. If someone knows of an individual who does well at the casino, the probability of that individual trying their luck is higher than an individual who does not know anyone or who has not won anything before.

How could you use standard scores and the standard distribution to compare the reading scores of two students receiving special reading resource help and one student in a standard classroom who does not get special help?

Comparing the standard scores and standard distribution from the two students receiving special resource help to the same scores from the individual who is not receiving special help can identify if the extra help is beneficial to two students receiving the help or not compared to the individual who is not receiving the extra help. That is confusing. When testing all three individuals with the same tools, one can identify where everyone is with the reading scores to find if the extra resources are beneficial or not.

In a standard normal distribution: What does a z score of 1 represent? What percent of cases fall between the mean and one standard deviation above the mean? What percent fall between the mean and –1 to +1 standard deviations from the mean? What percent of scores will fall between –3 and +3 standard deviations under the normal curve?

The empirical states that the bulk of data cluster around the mean in a normal distribution.

1. 68% of values fall within +- 1 standard deviation of the mean

2. 95% fall within +- 2 standard deviation of the mean

3. 99% fall with +- 3 standard deviations of the mean (Aron, Aron, & Coups, 2009).

References

Aron, A., Aron, E. N., & Coups, E. J. (2009). Statistics for psychology (5th ed.). Upper Saddle River, NJ: Pearson/Prentice Hall.

Green, S. B., & Salkind, N. J. (2011). Using SPSS for Windows and Macintosh: Analyzing and understanding data (6th ed.). Upper Saddle River, NJ: Pearson Education.

Salkind, N. J. (2011). Statistics for people who (think they) hate statistics (4th ed.). Thousand Oaks, CA: SAGE.

Copyright © XXXX by University of Phoenix. All rights reserved.

PSYCH/625 Statistics Practice Assignment

**Important information for writing discussion questions and participation**

Hi Class,

Please read through the following information on writing a Discussion question response and participation posts.

Contact me if you have any questions.

**Important information on Writing a Discussion Question**

- Your response needs to be a minimum of 150 words (not including your list of references)
- There needs to be at least TWO references with ONE being a peer reviewed professional journal article.
- Include in-text citations in your response
- Do not include quotes—instead summarize and paraphrase the information
- Follow APA-7th edition
- Points will be deducted if the above is not followed

**Participation –replies to your classmates or instructor**

- A minimum of 6 responses per week, on at least 3 days of the week.
- Each response needs at least ONE reference with citations—best if it is a peer reviewed journal article
- Each response needs to be at least 75 words in length (does not include your list of references)
- Responses need to be substantive by bringing information to the discussion or further enhance the discussion. Responses of “I agree” or “great post” does not count for the word count.
- Follow APA 7th edition
- Points will be deducted if the above is not followed

- Remember to use and follow APA-7th edition for all weekly assignments, discussion questions, and participation points.
- Here are some helpful links
- Student paper example
- Citing Sources
- The Writing Center is a great resource

**Welcome to class**

Hello class and welcome to the class and I will be your instructor for this course. This is a -week course and requires a lot of time commitment, organization, and a high level of dedication. Please use the class syllabus to guide you through all the assignments required for the course. I have also attached the classroom policies to this announcement to know your expectations for this course. Please review this document carefully and ask me any questions if you do. You could email me at any time or send me a message via the “message” icon in halo if you need to contact me. I check my email regularly, so you should get a response within 24 hours. If you have not heard from me within 24 hours and need to contact me urgently, please send a follow up text to.

I strongly encourage that you do not wait until the very last minute to complete your assignments. Your assignments in weeks 4 and 5 require early planning as you would need to present a teaching plan and interview a community health provider. I advise you look at the requirements for these assignments at the beginning of the course and plan accordingly. I have posted the YouTube link that explains all the class assignments in detail. It is required that you watch this 32-minute video as the assignments from week 3 through 5 require that you follow the instructions to the letter to succeed. Failure to complete these assignments according to instructions might lead to a zero. After watching the video, please schedule a one-on-one with me to discuss your topic for your project by the second week of class. Use this link to schedule a 15-minute session. Please, call me at the time of your appointment on my number. Please note that I will NOT call you.

Please, be advised I do NOT accept any assignments by email. If you are having technical issues with uploading an assignment, contact the technical department and inform me of the issue. If you have any issues that would prevent you from getting your assignments to me by the deadline, please inform me to request a possible extension. Note that working fulltime or overtime is no excuse for late assignments. There is a 5%-point deduction for every day your assignment is late. This only applies to approved extensions. Late assignments will not be accepted.

If you think you would be needing accommodations due to any reasons, please contact the appropriate department to request accommodations.

Plagiarism is highly prohibited. Please ensure you are citing your sources correctly using APA 7th edition. All assignments including discussion posts should be formatted in APA with the appropriate spacing, font, margin, and indents. Any papers not well formatted would be returned back to you, hence, I advise you review APA formatting style. I have attached a sample paper in APA format and will also post sample discussion responses in subsequent announcements.

Your initial discussion post should be a minimum of 200 words and response posts should be a minimum of 150 words. Be advised that I grade based on quality and not necessarily the number of words you post. A minimum of TWO references should be used for your initial post. For your response post, you do not need references as personal experiences would count as response posts. If you however cite anything from the literature for your response post, it is required that you cite your reference. You should include a minimum of THREE references for papers in this course. Please note that references should be no more than 5 years old except recommended as a resource for the class. Furthermore, for each discussion board question, you need ONE initial substantive response and TWO substantive responses to either your classmates or your instructor for a total of THREE responses. There are TWO discussion questions each week, hence, you need a total minimum of SIX discussion posts for each week. I usually post a discussion question each week. You could also respond to these as it would count towards your required SIX discussion posts for the week.

I understand this is a lot of information to cover in 5 weeks, however, the Bible says in Philippians 4:13 that we can do all things through Christ that strengthens us. Even in times like this, we are encouraged by God’s word that we have that ability in us to succeed with His strength. I pray that each and every one of you receives strength for this course and life generally as we navigate through this pandemic that is shaking our world today. Relax and enjoy the course!