1. The following table illustrates the BMI for a number of patients recently enrolled in a study investigating the relationship between BMI and type 2 diabetes. Participant BMI (kg/m2) A 26.5 B 19.2 C 29.7 D 27.4 E 30.2 F 28.9 A) Assuming the participants can be considered to be normally distributed, and that they come from a population with a σ=2.4 kg/m2, calculate a 95% confidence interval for the mean BMI of the population for which they represent. B) Correctly interpret the confidence interval you found above. 2. Suppose the following table illustrates the ages for a number of participants projected to enroll into a clinical trial looking at early onset of dementia. Patient Age A 64 B 57 C 58 D 53 E 71 F 54 G 63 A) Assuming that these participants can be considered to be normally distributed, and that they come from a population with a σ=4.3 years, calculate a 99% confidence interval for the mean age of the population for which they represent. B) With the same assumptions listed above, calculate a 90% confidence interval for the mean age of the population for which they represent. C) Compare the precision of the two confidence intervals. 3. A new vitamin supplementation program is intended to decrease average resting heart rate in individuals at risk for hypertension. Assume that a team of researchers are hopeful that resting heart rate in their population will get down to less than 68 bpm, in a population with a standard deviation of 2 bpm. In order to test this goal reduction, the team gathers a SRS of 273 participants in their program and calculates a sample average resting heart rate of 74 bpm. A) Carry out a one sample Z test to determine if the team can conclude that the supplementation program is successful in meeting their goal reduction in resting heart rate.  Use an α=0.05. B) Construct a 95% Confidence interval about the sample mean, and interpret the result. 4. A consulting company is hired to investigate the relationship between average physician annual income and number of beds present at a local hospital. Assume the following table represents a SRS of hospitals. Average Physician Annual Income($/year, X) Number of Beds (Count, Y) 127,655 698 176,526 943 134,253 713 114,534 578 A) Calculate basic descriptive statistics for your X and Y variables. B) Calculate a correlation coefficient, and interpret your result with respect to strength and direction. C) Calculate and correctly interpret your r2 for the data. 5. Assume that the following table of observations in a dataset represents a sample of physician incomes from a hospital. Create a box-plot for the data. Physician Income ($1000/year) Physician Income ($1000/year) A 121 G 176 B 124 H 138 C 173 I 169 D 175 J 158 E 186 K 163 F 143 L 154 6. Two oldsters were sitting on a park bench talking abou.

1. 1. The following table illustrates the BMI for a number of
patients recently enrolled in a study investigating the
relationship between BMI and type 2 diabetes.
Participant
BMI (kg/m2)
A
26.5
B
19.2
C
29.7

2. D
27.4
E
30.2
F
28.9
A) Assuming the participants can be considered to be normally
distributed, and that they come from a population with a σ=2.4
kg/m2, calculate a 95% confidence interval for the mean BMI of
the population for which they represent.
B) Correctly interpret the confidence interval you found above.
2.
Suppose the following table illustrates the ages for a number of
participants projected to enroll into a clinical trial looking at
early onset of dementia.
Patient

3. Age
A
64
B
57
C
58
D
53
E

4. 71
F
54
G
63
A) Assuming that these participants can be considered to be
normally distributed, and that they come from a population with
a σ=4.3 years, calculate a 99% confidence interval for the mean
age of the population for which they represent.
B) With the same assumptions listed above, calculate a 90%
confidence interval for the mean age of the population for
which they represent.
C) Compare the precision of the two confidence intervals.
3.
A new vitamin supplementation program is intended to decrease
average resting heart rate in individuals at risk for hypertension.
Assume that a team of researchers are hopeful that resting heart
rate in their population will get down to less than 68 bpm, in a
population with a standard deviation of 2 bpm. In order to test
this goal reduction, the team gathers a SRS of 273 participants

5. in their program and calculates a sample average resting heart
rate of 74 bpm.
A) Carry out a one sample Z test to determine if the team can
conclude that the supplementation program is successful in
meeting their goal reduction in resting heart rate. Use an
α=0.05.
B) Construct a 95% Confidence interval about the sample mean,
and interpret the result.
4.
A consulting company is hired to investigate the relationship
between average physician annual income and number of beds
present at a local hospital. Assume the following table
represents a SRS of hospitals.
Average Physician Annual Income($/year, X)
Number of Beds (Count, Y)
127,655
698
176,526

6. 943
134,253
713
114,534
578
A) Calculate basic descriptive statistics for your X and Y
variables.
B) Calculate a correlation coefficient, and interpret your result
with respect to strength and direction.
C) Calculate and correctly interpret your r2 for the data.
5.
Assume that the following table of observations in a dataset
represents a sample of physician incomes from a hospital.
Create a box-plot for the data.
Physician

7. Income ($1000/year)
Physician
Income ($1000/year)
A
121
G
176
B
124
H
138

8. C
173
I
169
D
175
J
158
E
186
K
163

9. F
143
L
154
6.
Two oldsters were sitting on a park bench talking about the old
days. The golfer bragged that he had a 76 average when he was
in his prime. The bowler snorted and said that his league
average was 210 when he was in his prime. What additional
information would you need to determine who was the better of
the two?
7.
Suppose a small group of expert physicists and mathematicians
held a joint conference. You, being an opportunistic sort, talked
them all into taking two personality tests. The first test
measured the need for achievement (N-Ach) and the second
measured the need for affiliation (N-Aff), which is a desire for
association with other people. Below are the scores. What
conclusions can you reach about the relationship between need
for achievement and need for affiliation among these scientists?
Person
X

10. Y
N-Ach
N-Aff
1 28 12
2 27 10
3 25 14
4 24 18
5 24 11
6 23 15
7 23 16
8 23 19
9 22 22
10 21 20
11 19 18
12 18 24
13 17 25
14 15 23

11. 15 13 26
8.
According to Obi-Wan Kenobe, the last of the Jedi Knights,
"The Force can have an influence on the weak-minded."
Unfortunately for psychology, concepts like a weak mind have
been abandoned and therefore psychologists cannot hope to
understand this most important intervening variable. Please
answer the following question which you will have no difficulty
with; which you will answer quickly, completely, and correctly.
The beautiful Princess Leia, in a prescience trance, saw a funny
hair style on 1920s movie stars in America. She decided to
adopt this hair style and practiced and practiced winding her
hair in circles using her ears as cores. On the average she got 12
coils and the standard deviation was two coils. What is the
probability that, on the day she was rescued by Luke, Han, and
Chewey, she had between 11 and 14 coils?
9.
A counselor at the local chapter of Impulse Buyers Anonymous
had just conducted a weekend workshop on how to be less
suggestible. To find out if the workshop had any effect, she had
each participant fill out a questionnaire that measured
suggestibility, with high scores indicating high suggestibility.
(Several such questionnaires exist.) Suppose that the national
norm (mean) for the questionnaire that was used was 25 and that
the participants produced the following statistics. Construct a
95 percent confidence interval and write a sentence of
interpretation that tells about the effect of the workshop.
SC = 242 SC2 = 5,413
N =
11

12. 10.
Identify each experiment below as an independent samples
design or a paired samples design.
a. At a hunting club the squirrel hunters had a contest with the
quail hunters to see who could hit the most moving targets.
b. A consumer-testing group compared Boraxo and Tide to
determine which got stuff whiter. Sheets that had been placed
for 12 hours in a bathtub of mud were washed and the amount of
light reflected was measured with a photometer.
c. Fifth-grade American Indians were matched as a group to a
group of New York Puerto Ricans on SES, IQ, and reading
level. They were then given a questionnaire on attitudes toward
school.
d. On the basis of a pretest on knowledge of foreign
governments, each student in the 9:00 class was matched with a
student in the 10:30 class. The 9:00 class used a "participant
approach" to the study of politics and the 10:30 class used the
"Heidleburg method." At the end of the term the same test was
given to both classes.
11.
Cowboys from the mythical Stats Bar-X Ranch competed in a
singing contest at the Dry Gulch Saloon where they sang against
cowpokes from the Dragging y Ranch. The songs were
psychowestern (which are like psychedelic songs, but with a
twangy ranch dressing). A Stats Bar‑X researcher counted the
number of people clapping after each song over the hour of the
contest, during which the two groups alternated singing.
a. Compare the two groups with a

13. t
test, find the effect size index, and write an interpretation of
what you find.
b. Find the 95 percent confidence interval about the mean
difference and write an interpretation.
Stats Bar-X
Dragging y
12:00 set 21 23
12:10 set 25 18
12:20 set 20 16
12:30 set 17 14
12:40 set 14 10
12:50 set 8 3