PU 515 Applied Biostatistics Final Exam 1. The following are body mass index (BMI) scores measured in 12 patients who are free of diabetes and participating in a study of risk factors for obesity. Body mass index is measured as the ratio of weight in kilograms to height in meters squared. Generate a 95% confidence interval estimate of the true BMI. 25 27 31 33 26 28 38 41 24 32 35 40 2. Consider the data in Problem #1. How many subjects would be needed to ensure that a 95% confidence interval estimate of BMI had a margin of error not exceeding 2 units? 3. A clinical trial is run to investigate the effectiveness of an experimental drug in reducing preterm delivery to a drug considered standard care and to placebo. Pregnant women are enrolled and randomly assigned to receive either the experimental drug, the standard drug or placebo. Women are followed through delivery and classified as delivering preterm (< 37 weeks) or not. The data are shown below. Preterm Delivery Experimental Drug Standard Drug Placebo Yes 17 23 35 No 83 77 65 Is there a statistically significant difference in the proportions of women delivering preterm among the three treatment groups? Run the test at a 5% level of significance. 4. Consider the data presented in problem #4. Previous studies have shown that approximately 32% of women deliver prematurely without treatment. Is the proportion of women delivering prematurely significantly higher in the placebo group? Run the test at a 5% level of significance. PU 515 Applied Biostatistics Final Exam 5. A study is run comparing HDL cholesterol levels between men who exercise regularly and those who do not. The data are shown below. Regular Exercise N Mean Std Dev Yes 35 48.5 12.5 No 120 56.9 11.9 Generate a 95% confidence interval for the difference in mean HDL levels between men who exercise regularly and those who do not. 6. A clinical trial is run to assess the effects of different forms of regular exercise on HDL levels in persons between the ages of 18 and 29. Participants in the study are randomly assigned to one of three exercise groups - Weight training, Aerobic exercise or Stretching/Yoga – and instructed to follow the program for 8 weeks. Their HDL levels are measured after 8 weeks and are summarized below. Exercise Group N Mean Std Dev Weight Training 20 49.7 10.2 Aerobic Exercise 20 43.1 11.1 Stretching/Yoga 20 57.0 12.5 Is there a significant difference in mean HDL levels among the exercise groups? Run the test at a 5% level of significance. HINT: SSwithin = 21,860. 7. Consider again the data in problem #6. Suppose that in the aerobic exercise group we also measured the number of hours of aerobic exercise per week and the mean is 5.2 hours with a standard deviation of 2.1 hours. The sample correlation is -0.42. a) Is there evidence of a s ...

1. PU 515
Applied Biostatistics
Final Exam
1. The following are body mass index (BMI) scores measured in
12 patients who are free of diabetes
and participating in a study of risk factors for obesity. Body
mass index is measured as the ratio of
weight in kilograms to height in meters squared. Generate a
95% confidence interval estimate of
the true BMI.
25 27 31 33 26 28 38 41 24 32 35 40
2. Consider the data in Problem #1. How many subjects would
be needed to ensure that a 95%
confidence interval estimate of BMI had a margin of error not
exceeding 2 units?

2. 3. A clinical trial is run to investigate the effectiveness of an
experimental drug in reducing preterm
delivery to a drug considered standard care and to placebo.
Pregnant women are enrolled and
randomly assigned to receive either the experimental drug, the
standard drug or placebo. Women
are followed through delivery and classified as delivering
preterm (< 37 weeks) or not. The data
are shown below.
Preterm Delivery Experimental Drug Standard Drug Placebo
Yes 17 23 35
No 83 77 65
Is there a statistically significant difference in the proportions
of women delivering preterm among
the three treatment groups? Run the test at a 5% level of
significance.
4. Consider the data presented in problem #4. Previous studies
have shown that approximately 32%
of women deliver prematurely without treatment. Is the
proportion of women delivering
prematurely significantly higher in the placebo group? Run the
test at a 5% level of significance.

3. PU 515
Applied Biostatistics
Final Exam
5. A study is run comparing HDL cholesterol levels between
men who exercise regularly and those
who do not. The data are shown below.
Regular Exercise N Mean Std Dev
Yes 35 48.5 12.5
No 120 56.9 11.9
Generate a 95% confidence interval for the difference in mean
HDL levels between men who
exercise regularly and those who do not.
6. A clinical trial is run to assess the effects of different forms
of regular exercise on HDL levels in
persons between the ages of 18 and 29. Participants in the
study are randomly assigned to one of

4. three exercise groups - Weight training, Aerobic exercise or
Stretching/Yoga – and instructed to
follow the program for 8 weeks. Their HDL levels are
measured after 8 weeks and are summarized
below.
Exercise Group N Mean Std Dev
Weight Training 20 49.7 10.2
Aerobic Exercise 20 43.1 11.1
Stretching/Yoga 20 57.0 12.5
Is there a significant difference in mean HDL levels among the
exercise groups? Run the test at a
5% level of significance. HINT: SSwithin = 21,860.
7. Consider again the data in problem #6. Suppose that in the
aerobic exercise group we also
measured the number of hours of aerobic exercise per week and
the mean is 5.2 hours with a
standard deviation of 2.1 hours. The sample correlation is -
0.42.
a) Is there evidence of a significant correlation between number
of hours of exercise per week and
HDL cholesterol level? Run the test at a 5% level of
significance.
b) Estimate the equation of the regression line that best

5. describes the relationship between number
of hours of exercise per week and HDL cholesterol level
(Assume that the dependent variable
is HDL level).
c) Estimate the HDL level for a person who exercises 7 hours
per week.
d) Estimate the HDL level for a person who does not exercise.
PU 515
Applied Biostatistics
Final Exam
8. The following data were collected in a clinical trial to
compare a new drug to a placebo for its
effectiveness in lowering total serum cholesterol. Generate a
95% confidence interval for the
difference in mean total cholesterol levels between treatments.
New Drug
(n=75)
Placebo
(n=75)
Total Sample
(n=150)

6. Mean (SD) Total Serum Cholesterol 185.0 (24.5) 204.3 (21.8)
194.7 (23.2)
% Patients with Total Cholesterol < 200 78.0% 65.0% 71.5%
9. A small pilot study is conducted to investigate the effect of a
nutritional supplement on total body
weight. Six participants agree to take the nutritional
supplement. To assess its effect on body
weight, weights are measured before starting the
supplementation and then after 6 weeks. The data
are shown below. Is there a significant increase in body weight
following supplementation? Run
the test at a 5% level of significance.
Subject Initial Weight Weight after 6 Weeks
1 155 157
2 142 145
3 176 180
4 180 175
5 210 209
6 125 126

7. 10. Answer True or False to each of the following
a) The margin of error is always greater than or equal to the
standard error.
b) If a test is run and p=0.0356, then we can reject H0 at
α=0.01.
c) If a 95% CI for the difference in two independent means is (-
4.5 to 2.1), then the point estimate
is -2.1.
d) If a 95% CI for the difference in two independent means is
(2.1 to 4.5), there is no significant
difference in means.
(
SC1040
:
Week
3
Assignment Worksheet
)
As you complete your weekly reading, answer the questions
below.
Please review the following writing guidelines prior to
answering the questions:
· Remember to respond to the questions using your own words.
· Do NOT copy responses from the textbook, internet or other
resources. This is plagiarism, which is illegal, and may result
in a failing grade.
· You MUST paraphrase information in your own words and not
transfer word-for-word.
· For information on how to avoid plagiarism, please visit the

8. Writing Center in the Student Success Center.
Part 1: Energy is the capacity to do work. Like our planes,
trains, and automobiles, living organisms need energy to
function.
After reading pages 76 – 77 in your textbook, explain how
energy flows one-way from the environment into living
organisms.
10 points
Answer:
Type your answer here
Part 2: For the numerous chemical reactions to occur in a living
cell, enzymes are needed.
After reading pages 80 – 81 in your textbook, discuss how
enzymes work. Include in your discussion the following terms:
substrate, active site, enzyme, and activation energy.
10 points
Answer:
Type your answer here
(See next page for part 3)
(
Type your name here
)
Part 3: As these numerous chemical reactions occur in a cell,
they take the form of either a linear pathway or a cycle.

9. After reading page 82 in your textbook, describe the linear
pathway and a cyclic pathway.
10 points
Answer:
Type your answer here
Part 4: For cells to operate in metabolic pathways, they must
move substances in and out.
After reading pages 84 – 87 in your textbook, define
concentration and concentration gradient.
10 points
Answer:
Type your answer here
Part 5: The two major metabolic reactions that occur in cells are
photosynthesis and cellular respiration. Photosynthesis only
occurs in cells that can use the energy from sunlight to make
chemicals, plant cells. Cellular respiration occurs in all cells.
After reading pages 64, 65, 97, and 112 in your textbook,
describe the structure of the following.
10 points
Describe the structure of a chloroplast.
Type your answer here

10. 5 points
Describe the structure of a mitochondria.
Type your answer here
5 points
(See next page for part 6)
(
Type your name here
)
Part 6: Photosynthesis is incredibly important for all life. It
takes place within a chloroplast, and is the process that converts
the energy of sunlight into chemical energy that is used to fuel
life on earth.
After reading pages 97 –100 in your textbook, outline the
reactions of the following.
10 points
Outline the light-dependent reactions of photosynthesis.
Type your answer here
5 points
Outline the light-independent reactions of photosynthesis.
Type your answer here
5 points
Part 7: We have learned that mitochondria are the powerhouse
of all cells! The proper functioning of these complex structures
is critical. Unfortunately, things can and do go wrong!
After reading pages 109 – 119 in your textbook, state which

11. process (glycolysis, Krebs cycle, or Electron Transfer
Phosphorylation) is not properly functioning in each scenario.
10 points
Carbon dioxide is not being produced.
Type your answer here
5 points
Hydrogen ions are not properly moving across the mitochondrial
membrane.
Type your answer here
5 points
You will earn additional points if you correctly submit the
worksheet to the assignment dropbox.
5 points
You will earn additional points if you use proper sentence
structure, grammar and spelling.
5 points
Revised 6/16/14
W
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E
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3
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ISCUSSION
I
NSTRUCTIONS
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1
of
1
Week
3
Discussion
Di
s
cuss the following:
About one in 5,000 people worldwide suffers from a genetic
disorder caused by a defect in
their mitochondria. Few if any of these disorders are being
investigated for possible cures,
because developing a new drug is a very expensive process, and
there aren't enough people
suffering from these conditions to justify the expense.
Should governments shoulder the cost of developing drugs that
are designed to help only a
very small fraction of the population? What do you think should
be done?
Grading
To receive full participation points, you must meet the
following criteria:
Criteria
Points
Post one original response to the question by Wednesday at
11:59 pm
Eastern Time
. Your response should include the following:
•
Offer substantive comments.
•
Your posting is appropriate to the content being covered.
25

13. Reply to at least two classmates by Sunday at
11:59 pm Eastern Time
.
Your
r
eply to your classmates should:
•
Be respectful of the opinions and ideas of others.
•
Say more than "I agree", "I disagree" or " Great job!"
5
Total Points