This document contains instructions and questions for a statistics assignment involving probability, confidence intervals, hypothesis testing using t-tests and ANOVA, chi-square tests, and matching statistical tests to research situations. It includes 14 multiple choice and short answer questions requiring calculations and interpretations of statistical analyses on sample data using the StatCrunch software.

1. Week 2 Assignment
1. A. What is the probability of rolling a four in the gambling
dice game of craps (given two six sided dice)?
B. What is the probability that a player can roll a four 3 times
in a row (assume that rolling the dice each time does not affect
the outcome of the next roll)?
2. Population A and Population B both have a mean height of
70.0 inches with an SD of 6.0. A random sample of 30 people
is picked from population A, and random sample of 50 people is
selected from Population B. Which sample mean will probably
yield a more accurate estimate of its population mean? Why?
3.
Suppose we obtained data on vein size after application of a
nitroglycerin ointment in a sample of 50 patients. The mean
vein size is found to be 7.8mm with an SD of 2.1. Using a t
distribution table, what are the confidence limits for a 95%
confidence interval? For a 99% confidence interval?
4.
In a pilot study evaluating the use of a new drug to lower
resting heart rates (HR) of patients, the following data was
recorded:
Subject #
Resting HR
001
72
002
88
003
71
004
87

2. 005
64
006
77
007
79
008
59
009
66
010
68
011
78
012
89
013
91
014
81
015
77
016
75
017
69
Given that the average resting HR of the general population for
this study is 72, use StatCrunch to perform the appropriate t
test. What is the value of t? Using an alpha of 0.05, is the t
statistic significant? Why? What are the confidence limits for
a 95% confidence interval here and what do they mean for this
patient group? Copy and Paste your work from StatCrunch into
your Word document submission.
5.
Write one or two sentences that could be used to report the

3. results obtained for the t-test in Exercise 4.
6.
For which of the following situations is the independent groups
t-test appropriate (if inappropriate, why?):
a.
The independent variable is infant birth weight at one week
(normal vs high); the dependent variable is resting heart rate.
b.
The independent variable is radiation treatment on throat cancer
patients (after a low dose and then a high dose treatment); the
dependent variable is white blood cell count.
c.
The IV is infant birth weight (low vs normal birth weight); the
DV is number of days absent from school in first grade.
d.
The IV is gender (male vs female); the DV is compliance vs
noncompliance with a medication regimen.
e.
The independent variable is married status (single vs divorced
vs married); the dependent variable is happiness measured on a
scale from 1 to 50
7.
For which of the following situations is the dependent groups t-
test appropriate (if not appropriate, why?)
a.
The IV is presence or absence of conversation directed to
comatose patients (same patients with and without
conversation); the DV is the patients’ intracranial pressure.
b.

4. The IV is birth type (home vs hospital); the DV is perceived
functional ability of the patient 48 hours after surgery.
c.
The IV is time since incarceration (1 months vs 3 months vs 6
months); the DV is body weight.
d.
The IV is menopausal state (pre vs post); the DV is attitudes
toward menopause.
e.
The IV is nap therapy for narcoleptics (same patients before vs
after treatment); the DV is the type of nap they had the
following week (had unplanned vs didn’t have unplanned nap).
8.
Suppose we wanted to test the hypothesis that a control group of
cancer patients (Group 1) would report higher mean pain ratings
than an experimental group receiving special massage
treatments (Group 2). Use the following information. Compute
a t-statistic for independent groups:
mean group 1 = 78.1
SD21 = 42.1
n1 = 25
mean group 2 = 75.1
SD22 = 39.7
n2=25

5. What are the degrees of freedom and the value of t ? Using
α=0.05 for a two-tailed test, is this t statistic significant? Show
your calculations (or StatCrunch output) for full credit.
9.
Write one or two sentences that could be used to report the
results obtained for the t-test in Exercise 8.
10.
For each of the following t values, indicate whether the t is
statistically significant for a two-tailed test, at the specified
alphas:
a. t = 2.90, df = 25, α = 0.01
b. t = 2.00, dr = 25, α = 0.05
c. t = 5.52, df = 10, α = 0.01
d. t = 2.02, df = 150, α = 0.05
11.
For each of the following situations, indicate whether ANOVA
is appropriate; if not appropriate, the reason why not; and, if
appropriate, the type of ANOVA that would be used (i.e., one-
way, repeated measures, etc.)
a.
The IVs are ethnicity (Asian, White, African American,
Hispanic) and gender (male vs female); the DV is serum
cholesterol levels.
b.
The IV is smoking status – smokers vs non-smokers; the DV is
health-related hardiness as measured on a 20-item scale.
c.

6. The IV is maternal breast feeding status (breastfeeds daily vs
breastfeeds at least 1-3 times/week vs doesn’t breastfeed); the
DV is maternal bonding with infant, as measured on a 20-item
self-report scale.
d.
The IV is treatment group for patients with drug-induced
shivering (extremity wraps vs high room temp vs normal room
temp without wraps) same patient used for each treatment; the
DV is myocardial oxygen consumption, measured before and
after treatment.
e.
The IV is length of gestation (preterm vs term vs postterm); the
DV is delivery type (vaginal vs Caesarean).
12.
Suppose we wanted to compare the somatic complaints (as
measured on a scale known as the Physical Symptom Scale or
PSS) of three groups of people: non-smokers, smokers, and
people who recently quit smoking. Using the following data
for PSS, do a one-way ANOVA to test the hypothesis that the
population means are equal:
NonsmokersSmokers
Quitters
19
31
30

7. 28
29
22
17
22
23
20
24
22
25

8. 19
17
Using StatCrunch, determine the means for the three groups and
compute the sums of squares, degrees of freedom, and mean
squares for these data. What is the value of F? Using an alpha
of 0.05, is the F statistic significant? Why? Copy and Paste
your work from StatCrunch into your Word document
submission.
13.
A new motorcycle is being developed to meet new gas mileage
standards recently passed by the federal government. An
engineer tested three model designs by randomly assigning the
motorcycles in a blind study (the riders recorded the mileage
but did not know the design of the motorcycle, only its code).
The data in miles per gallon (MPG) for the three designs is
listed below:
X-1
B-1
Z-1
45
55
54
62
55
52
50
54
41
65
44
35

9. 62
52
38
50
69
41
50
58
51
58
45
44
Using StatCrunch, determine the means for the three groups
and compute the sums of squares, degrees of freedom, and mean
squares for these data. What are the hypotheses to be tested
here? What is the value of F? Using an alpha of 0.05, is the F
statistic significant? Why? Copy and Paste your work from
StatCrunch into your Word document submission for full credit.
14.
For each of the following F values, indicate whether the F is
statistically significant at the specified alpha level:
a.
F = 4.80, df = 4, 40 α = 0.01
b.
F = 5.02, df = 3, 60, α = 0.001
c.
F = 3.45, df = 3, 27, α = 0.05
d.
F = 4.99, df = 2, 150, α = 0.01

10. e.
F = 2.09, df = 2, 250, α = 0.05
Week 3 Assignment
1.
Using StatCrunch, calculate the chi-square statistic and degrees
of freedom for the following set of data for 300 people:
Group A
Group B
Group C
Total
Had flu shot
20
30
32
82
Didn’t have flu shot
80
70
68
218

11. Total
100
100
100
300
Is the value of the chi-square statistically significant at the 0.05
level?
2.
Write a paragraph summarizing the results of the analysis in
Exercise 1.
3.
Using StatCrunch, calculate the chi-square statistic and degrees
of freedom for the following set of data for 180 people
undergoing a knee replacement treatment with a drug
supplement:
Treatment with drug X Treatment without Drug X
Total
Had > 8 wk rehab
18
32

12. 50
Had < 8 wk rehab
70
60
130
Total
88
92
180
Is the value of the chi-square statistically significant at the 0.05
level?
4.
Write a paragraph summarizing the results of the analysis in
Exercise 3.
5.
Given each of the following circumstances, determine whether
the calculated values of chi-square are statistically significant:

13. a. χ2 = 3.02, df = 1, α = 0.05
b. χ2 = 8.09, df = 4, α = 0.05
c. χ2 = 10.67, df = 3, α = 0.01
d. χ2 = 9.88, df = 2, α = 0.01
6.
Match each of the nonparametric tests in Column A with its
parametric counterpart in Column B
A. Nonparametric Test
B. Parametric Test
1. Mann-Whitney U-test
a. Paired t-test
2. Friedman test
b. One-way ANOVA
3. Kruskall-Wallis test
c. Independent groups t-test

14. 4. Wilcoxon signed-ranks test
d. Repeated measures ANOVA
7.
Using the information provided, indicate which statistical test
you think should be used for each of the following situations:
a. Independent variable: normal birth weight vs. low birth
weight infants; dependent variable: 1 minute Apgar scores (1-10
scale).
b. Independent variable: time of measurement (before, during,
and after surgery); dependent variable: heart rate.
c. Independent variable: time of measurement (before, during,
and after intervention); dependent variable: did vs did not
exercise regularly.
d. Independent variable: infertility treatment A vs infertility
treatment B vs control condition; dependent variable: did vs did
not become pregnant.
8.
Below are three sets of expected frequencies for the four cells
of 2 X 2 contingency tables. Identify which statistical
procedure would be appropriate for each, using the most
conservative approach.
a.
4 4
b.
35 35

15. c.
9 9
21 21
65 65
91 91