v
PSYC354 Homework 4 complete solutions correct answers key
Sampling and Probability
When submitting this file, be sure the filename includes your full name, course and section. Example: HW4_JohnDoe_354B01
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.
Part I: Concepts
Questions 1–15
These questions are based on the Nolan and Heinzen reading and end-of-chapter questions.
Questions 1-10
Fill in the highlighted blanks to answer/complete the statements.
1)
When a sample has similar characteristics to the population from which it was drawn, the sample is said to be ________.
2)
If a finding based on a sample also applies beyond that sample to the entire population, that finding is said to have high external _______.
3)
The duplication of the results of a research study in a different context or with a different sample is called ________.
4)
Your own estimate of the likelihood that you will win a contest is known as a(n) ________.
5)
Expected relative-frequency probability is computed as the number of ________ divided by the number of ________.
6)
The ________ group is the group receiving the intervention or treatment of interest.
7)
A statement that 2 populations are different from one another is a(n) ________ hypothesis.
8)
If you find that the groups you studied differed from each other more than would be expected by chance alone, you ________ the null hypothesis.
9)
When you fail to reject the null hypothesis but the null hypothesis is in fact false, you have made a(n) ________ error.
10)
When you reject the null hypothesis but the null hypothesis is in fact true, you have made a(n) ________ error.
Question 11a-11b
A school psychologist is interested in whether longer recess breaks affect time on task in the classroom. She divides students into two groups: one with a standard recess length of 10 minutes, and one with a longer recess length of 18 minutes, and assesses their time on task in the classroom over a period of 4 weeks.
11-a) What is the likely null hypothesis for this experiment?
Answer
11-b) What is the likely research hypothesis for this experiment?
Answer
Question 12-15
Complete the following exercises:
12) What is the probability of hitting a target if, in the long run, 15 out of every 125 attempts actually hit the target?
Answer (show work)
13) On a TV game show, 6 people have won the grand prize and a total of 159 people have competed. Estimate the probability of winning the grand prize.
Answer (show work)
14) Convert the following proportions to percentages:
a) 0.356
b) .9
c) .1742
a)
Answer
b)
Answer
c)
Answer
15) Convert the following percentages to proportions:
a) 57.8%
b) .5%
c) 3.3%
a)
Answer
b)
Answer
c)
Answer
Part II & Part III
There is no new SPSS material this module/week. No questions for Part II or III
.
Part IV: Cumulative
Data provided below for Questions 1 and 2.
Grade
99.00
96.00
92.00
89.00
85.00
80.00
78.00
76.00
75.00
74.00
72.00
70.00
70.00
67.00
63.00
59.00
53.00
Part IV:
Questions 1a-1b
The final grades for students in a freshman seminar are shown in the left-hand column. Enter the data into a new SPSS data file.
· Create the appropriate SPSS graph to show the distribution of students’ grades.
· Compute descriptive statistics for this data.
· Which measure of central tendency would you use to describe this data?
· Why?
1-a)
Create the appropriate SPSS graph to show the distribution of students’ grades.
Answer: SPSS graph
1-b)
Compute descriptive statistics for this data.
Which measure of central tendency would you use to describe this data?
Why?
Answer: Appropriate Descriptive Statistics Table
Answer: Measure Of Central Tendency
Explanation/Justification:
City
Livability Rating
Boston
Austin
Chicago
Pittsburgh
San Diego
Jacksonville, FL
Detroit
Miami
New York
Portland
Atlanta
Charlotte
73
83
73
75
80
72
67
71
73
80
78
77
Part IV:
Questions 2a & 2b
· The overall livability ratings of 12 US cities appear in the columns to the left.
· The data are based on data taken from this livability calculator (http://www.areavibes.com/).
· Enter the data in a new SPSS file. When creating the City variable, be sure that the type is set to “string” or “text” in the Variable View window so that the names will show up on the graph.
2-a)
Create the correct type of graph to display this data, and justify your choice of graph.
Answer: paste SPSS graph here
Explanation/Justification:
2-b)
What level of measurement (nom., ord., scale) is the variable “City”?
What level of measurement is the variable “Livability Rating”?
Answer
Answer
Submit Homework 4 by 11:59 p.m. (ET) on Monday of Module/Week 4. Remember to name file appropriately.
Done!