PSYC 510
HOMEWORK 4
Data Organization and Descriptive Statistics
When submitting this file, be sure the filename includes your full name, course and section.
Part I: General Concepts
These questions are based on the concepts covered in this week’s assigned readings and
presentations.
Example: HW4_JohnDoe_510B01
Be sure you have reviewed this module/week’s lesson and presentations along with the practice
data analysis before proceeding to the homework exercises. Complete all analyses in SPSS, then
copy and paste your output and graphs into your homework document file. Answer any written
questions (such as the text-based questions or the APA Participants section) in the appropriate
place within the same file.
All questions are worth 2 points.
1. The following data represents 30 emotional intelligence test scores. Organize these data into
a class interval frequency distribution using 11 intervals with frequency (f) and relative
frequency (rf) columns.
30 47 53 57 61 67
40 49 55 58 62 68
41 50 56 58 64 70
45 51 57 59 64 71
46 52 57 59 65 73
Class Intervals (use whole numbers) f rf (round to 2 decimals)
30-33 1 0.03
34-37 0 0.00
38-41 2 0.07
42-45 1 0.03
46-49 3 0.10
50-53 4 0.13
54-57 5 0.17
58-61 5 0.17
62-65 4 0.13
66-69 2 0.07
70-73 3 0.10
N = 30 1.00
2. What is the range of the data (show your
calculation).
Answer: 43
73-30=43
PSYC 510
3. What is the class width? Answer: 4
4. What is the upper class limit of the first
interval?
Answer: 41
Answer the following questions related to your assigned readings and presentations.
5. You want to graph the number of times individual
people attendend church last year. What type of
graph is most appropriate? (make sure you think
about whether data is discrete or continuous)
Answer: line graph
6. What measure of central tendency is the most
reliable indicator of a central tendency of a
distribution if the data is ordinal?
Answer: median
7. Which graph type is most appropriate for nominal
data?
Answer: bar graph
8. What is the symbol for the number of scores in a
distribution?
Answer: N
9. What is the symbol for the mean of a sample? Answer: x
“x-bar”
Use the following numbers to calculate the following by hand (must show all work and do NOT
round)
79935
10. What is the mean? Answer: 6.6
11. What is the median? Answer: 7
12. What is the mode? Answer: 9
13. Is this data best described as Answer: negatively skewed
normal, positively skewed, or
negatively skewed?
14. Justify your answer to #13. Answer: because the left side of the tail is shaded wich
represents negative
PSYC 510
A survey of college students was conducted during final exam week to assess the number of cups
of coffee consumed each day. The mean number of cups was 2 with a standard deviation of 0.5
cups. The distribution was normal. Make sure you do NOT round when answering any of these
questions and that you use your Jackson e-book for exact values. When applicable, show ALL work
for full points.
15. If Nancy had 3 cups of coffee, what is her z score? Answer: 2=
5=2
(3-2)/0.
16. Which of the following curves (A, B, or C) best illustrate where
her data would fall?
Answer: b
17. What proportion of students drank more cups of coffee than
Nancy?
Answer: 5% of students
ore cups of coffee
ncy
drank m
than Na
18. If you wanted to calculate how many cups of coffee an
individual at the 33th percentile drank, which of the following
curves (A, B, or C) best indicates where this would fall?
Answer: a
19. What z score most closely represents an individual at the 33th
percentile? (Remember: if it is to the left of the middle, it will
be negative; if it is to the right of the middle, it is positive.)
Answer: -0.44
Part II: SPSS Application
These questions require the use of SPSS. Remember you must submit all of your work
within this word document. You will need to take a screen shot of your data view if
necessary, or copy and paste your output into the spaces below.
PSYC 510
The following dataset contains scores for depression, a subscale on the DASS-21 from 24 individuals.
This variable is considered scale and is discrete. Enter the following data into SPSS to answer the
following questions. Make sure you name the variable “Depression”.
11 13 15 17 18 22 23 15
7 8 18 17 13 11 15 18
9 16 18 12 13 15 14 17
23. Insert the descriptive statistics table (NOT the frequency table) from your SPSS output.
Insert table here:
Answer the following question related to the use of SPSS.
22. Which view are you using when you enter the
names of your variables – the Data View, Variable
View, or Output Window?
Answer: variable view
20. How many cups of coffee would an individual at the 33th
percentile rank drink? (do NOT round your final answer)
Answer: 2-0.44(0.5)-1.78
21. Determine the proportion of scores that fall between the
positive z-scores of 0.75 and 1.25.
Answer: 0.8944-
0.7734=0.121
PSYC 510
24. Create a histogram of the data using SPSS and paste it below.
Insert SPSS graph here:
PSYC 510
As part of his dissertation, Joe wanted to know if anxiety about having to take a required
statistics course differs between psychology and business majors. He developed a new
measure to assess subject-specific anxiety on a scale of 0 – 100, with a higher number
indicating more anxiety (any value was possible – even decimals).
25. What is the independent variable? Answer: Gender
26. Is the independent variable a true manipulated
variable or a subject variable?
Answer: subject variable
27. What is the dependent variable? Answer: anxiety
28. What is the scale of measurement of the DV? Answer: ratio scale
29. If he wanted to administer a similar (but not
identical) form of the test to the same people at two
different times, what type of reliability is he
assessing?
Answer: Test-retest reliability
30. What type of validity would be examined by
comparing results from his new measure of math
anxiety to well developed survey on math anxiety?
Answer: Construct validity
Part III: Cumulative
These questions can be related to anything covered thus far in the course.
Done!
Submit Homework 4 by 11:59 p.m. (ET) on Sunday of Module/Week 4. Remember to name file
appropriately.
