Assignment: People’s Hated Statistics.
Assignment: People’s Hated Statistics.
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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.
Why is a z score a standard score? Why can standard scores be used to compare scores from different distributions?
- 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 | ? |
? | –1.6 |
82.0 | ? |
? | 1.8 |
69.0 | ? |
? | –0.5 |
85.0 | ? |
? | 1.7 |
72.0 | ? |
- Questions 3a through 3d are based on a distribution of scores with and the standard deviation = 6.38. Draw a small picture to help you see what is required.
- What is the probability of a score falling between a raw score of 70 and 80?
- What is the probability of a score falling above a raw score of 80?
- What is the probability of a score falling between a raw score of 81 and 83?
- What is the probability of a score falling below a raw score of 63?
- 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?
- 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 | |||
Talya |
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 thedata 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).
- Using IBM® SPSS® software, conduct a frequency analysis on the gender and marital status variables. From the output, identify the following:
- Percent of men
- Mode for marital status
- Frequency of divorced people in the sample
- Using IBM® SPSS® software, create a frequency table to summarize the data on the educational level variable.
The data for Exercise 8 is available in the data file named Lesson 21 Exercise File 1.
- 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:
- Skewness
- Mean
- Standard deviation
- Kurtosis
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? | ||
How does understanding probability help you understand statistics? | ||
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? | ||
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? | ||