University of Phoenix Material

Time to Practice – Week Four

Complete Parts A, B, and C below.

Part A

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

1. Using the data in the file named Ch. 11 Data Set 2,
test the research hypothesis at the .05 level of significance that boys raise
their hands in class more often than girls. Do this practice problem by hand
using a calculator. What is your conclusion regarding the research hypothesis?
Remember to first decide whether this is a one- or two-tailed test.

2. Using the same data set (Ch. 11 Data Set 2), test
the research hypothesis at the .01 level of significance that there is a
difference between boys and girls in the number of times they raise their hands
in class. Do this practice problem by hand using a calculator. What is your
conclusion regarding the research hypothesis? You used the same data for this
problem as for Question 1, but you have a different hypothesis (one is
directional and the other is nondirectional). How do the results differ and
why?

3. Practice the following problems by hand just to see
if you can get the numbers right. Using the following information, calculate
the t test statistic.

a.

14X1 = 62 X2 = 60 n1 = 10 n2 = 10 s12= 6 s22= 10″>

b.

14X1 = 158 X2 = 157.4 n1 = 22 n2 = 26 s12= 4.23 s22= 6.73″>

c.

14X1 = 200 X2 = 198 n1 = 17 n2 = 17 s12= 6 s22= 5.5″>

4. Using the results you got from Question 3 and a
level of significance at .05, what are the two-tailed critical values
associated with each? Would the null hypothesis be rejected?

5. Using the data in the file named Ch. 11 Data Set 3,
test the null hypothesis that urban and rural residents both have the same
attitude toward gun control. Use IBM® SPSS®software to
complete the analysis for this problem.

6. A public health researcher tested the hypothesis
that providing new car buyers with child safety seats will also act as an
incentive for parents to take other measures to protect their children (such as
driving more safely, child-proofing the home, and so on). Dr. L counted all the
occurrences of safe behaviors in the cars and homes of the parents who accepted
the seats versus those who did not. The findings: a significant difference at
the .013 level. Another researcher did exactly the same study; everything was
the same—same type of sample, same outcome measures, same car seats, and so on.
Dr. R’s results were marginally significant (recall Ch. 9) at the .051 level. Which
result do you trust more and why?

7. In the following examples, indicate whether you
would perform a t test of independent
means or dependent means.

a. Two groups were exposed to different treatment levels
for ankle sprains. Which treatment was most effective?
b. A researcher in nursing wanted to know if the
recovery of patients was quicker when some received additional in-home care
whereas when others received the standard amount.
c. A group of adolescent boys was offered
interpersonal skills counseling and then tested in September and May to see if
there was any impact on family harmony.
d. One group of adult men was given instructions in
reducing their high blood pressure whereas another was not given any
instructions.
e. One group of men was provided access to an exercise
program and tested two times over a 6-month period for heart health.

8. For Ch. 12 Data Set 3, compute the t value and write a conclusion on whether
there is a difference in satisfaction level in a group of families’ use of
service centers following a social service intervention on a scale from 1 to
15. Do this exercise using IBM®SPSS®software, and report
the exact probability of the outcome.

9. Do this exercise by hand. A famous brand-name
manufacturer wants to know whether people prefer Nibbles or Wribbles. They
sample each type of cracker and indicate their like or dislike on a scale from
1 to 10. Which do they like the most?

Nibbles rating

Wribbles rating

9

4

3

7

1

6

6

8

5

7

7

7

8

8

3

6

10

7

3

8

5

9

2

8

9

7

6

3

2

6

5

7

8

6

1

5

6

5

3

6

10. Using the following table, provide three examples
of a simple one-way ANOVA, two examples of a two-factor ANOVA, and one example
of a three-factor ANOVA. Complete the table for the missing examples. Identify
the grouping and the test variable.

Design

Grouping variable(s)

Test variable

Simple ANOVA

Four levels of hours of
training—2, 4, 6, and 8 hours

Typing accuracy

Enter Your Example Here

Enter Your Example Here

Enter Your Example Here

Enter Your Example Here

Enter Your Example Here

Enter Your Example Here

Two-factor ANOVA

Two levels of training
and gender (two-way design)

Typing accuracy

Enter Your Example Here

Enter Your Example Here

Enter Your Example Here

Enter Your Example Here

Three-factor ANOVA

Two levels of training,
two of gender, and three of income

Voting attitudes

Enter Your Example Here

Enter Your Example Here

11. Using the data in Ch. 13 Data Set 2 and the IBM®
SPSS®software, compute the F ratio for a comparison between the three levels representing the
average amount of time that swimmers practice weekly (< 15, 15–25, and > 25
hours) with the outcome variable being their time for the 100-yard freestyle. Does
practice time make a difference? Use the Options feature to obtain the means for
the groups.

12. When would you use a factorial ANOVA rather than a
simple ANOVA to test the significance of the difference between the averages of
two or more groups?

13. Create a drawing or plan for a 2 × 3 experimental
design that would lend itself to a factorial ANOVA. Identify the independent
and dependent variables.

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

PartB

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

The data for Exercise
14 is in the
data file named Lesson 22 Exercise File 1.

14. John is interested in determining if a new teaching
method, the involvement technique, is effective in teaching algebra to first
graders. John randomly samples six first graders from all first graders within
the Lawrence City School System and individually teaches them algebra with the
new method. Next, the pupils complete an eight-item algebra test. Each item
describes a problem and presents four possible answers to the problem. The
scores on each item are 1 or 0, where 1 indicates a correct response and 0
indicates a wrong response. The IBM®SPSS® data file
contains six cases, each with eight item scores for the algebra test.

Conduct a one-sample t test on
the total scores. On the output, identify the following:

a. Mean algebra score
b. T test value
c. P value

The data for Exercise
15 is in thedata
file named Lesson 25 Exercise File 1.

15. Marvin is interested in whether blonds, brunets,
and redheads differ with respect to their extrovertedness. He randomly samples
18 men from his local college campus: six blonds, six brunets, and six
redheads. He then administers a measure of social extroversion to each
individual.

Conduct a one-way ANOVA to investigate the relationship between hair
color and social extroversion. Conduct appropriate post hoc tests. On the
output, identify the following:

a. F ratio for the group effect
b. Sums of squares for the hair color effect
c. Mean for redheads
d. P value for the hair color effect

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

PartC

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

Cite any sources consistent
with APA guidelines.

Question

Answer

What is meant by independent samples?
Provide a research example of two independent samples.

When is it appropriate to use a t test for dependent samples? What is
the key piece of information you must know in order to decide?

When is it appropriate to use an ANOVA?
What is the key piece of information you must know in order to decide?

Why would you want to do an ANOVA when
you have more than two groups, rather than just comparing each pair of means
with a t test?

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