STAB22 midterm

Answer Key for Exam A
1. In an effort to improve the overall health and well-being of its employees, a large
corporation distributed a written survey to each of its 1400 employees. Data collected
included number of hours worked per week, number of hours spent exercising per
week, number of hours spent enjoying hobbies per week, and number of hours spent
with family/friends per week.
Determine the W’s.
(a) Who: 1400 employees;
What: Number of hours spent exercising per week;
When: Not specified;
Where: Large corporation;
Why: To devise a health club plan
(b) Who: 1400 employees;
What: Number of hours worked per week, number of hours spent exercising per
week, number of hours spent enjoying hobbies per week, and number of hours
spent with family/friends per week;
When: Not specified;
Where: Large corporation;
Why: To improve the health and well-being of its employees
(c) Who: Large corporations;
What: Number of hours worked per week.;
When: Not specified;
Where: Large corporation;
Why: To improve the health and well-being of its employees
(d) Who: 1400 employees;
What: Overall job satisfaction;
When: Not specified;
Where: Large corporation;
Why: To improve the health and well-being of its employees
(e) Who: A large corporation;
What: Overall job satisfaction;
When: Not specified;
Where: Large corporation;
Why: To improve the health and well-being of its employees
Solution:
b 




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,2. An Ontario hospital concerned about the rising number of low birth weight babies
collected data from 300 births over a five year time span. They recorded the mother’s
insurance number (unique number assigned to each person), the mother’s age, the
mother’s prepregnancy weight, the level of prenatal care (none, minimal, adequate),
and whether the mother used drugs during pregnancy (cigarettes, alcohol, etc.).
Which of the following statements is true?
(a) Mother’s insurance number is a quantitative variable; mother’s age is a quan-
titative variable; mother’s prepregnancy weight is a quantitative variable; level
of prenatal care is a categorical variable; mother’s drug use is a quantitative
variable
(b) Mother’s insurance number is a quantitative variable; mother’s age is a quan-
titative variable; mother’s prepregnancy weight is a quantitative variable; level
of prenatal care is a quantitative variable; mother’s drug use is a categorical
variable
(c) Mother’s insurance number is a quantitative variable; mother’s age is a quanti-
tative variable; mother’s prepregnancy weight is a quantitative variable; level of
prenatal care is a categorical variable; mother’s drug use is a categorical variable

(d) Mother’s insurance number is an identifier; mother’s age is a quantitative vari-
able; mother’s prepregnancy weight is a quantitative variable; level of prenatal
care is a categorical variable; mother’s drug use is a categorical variable
(e) Mother’s insurance number is an identifier; mother’s age is a categorical variable;
mother’s prepregnancy weight is a quantitative variable; level of prenatal care
is a categorical variable; mother’s drug use is a categorical variable
Solution:
d 




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, 3. A company held a blood pressure screening clinic for its employees. The results are
summarized in the table below by age, group and blood pressure level.
What is the approximate marginal distribution of blood pressure level?




(a) 21% low, 40% normal, 40% high
(b) 21% under 30, 40% between 30-49, 40% over 50
(c) 21% low, 50% normal, 29% high
(d) 23% low, 57% normal, 20% high
(e) 27% low, 101% normal, 40% high
Solution:
c 
4. A company held a blood pressure screening clinic for its employees. The results are
summarized in the table below by age, group and blood pressure level.
What is the approximate conditional distribution of blood pressure level for employees
over 49?




(a) 7% low, 20% normal, 14% high
(b) 23% low, 47% normal, 30% high
(c) 29% low, 47% normal, 24% high
(d) 17% low, 48% normal, 35% high
(e) 22% low, 48% normal, 31% high
Solution:
d 




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