WGU C955 APPLIED PROBABILITY AND
STATISTICS CORE REVIEW SHEET 2026
DESCRIPTIVE STATISTICS AND DATA
INTERPRETATION SKILLS
◉ A study is being conducted on the relationship between age and
the amount of money people spend on eating out. Researchers
gather data from a group of 100 people ages 50 to 65 and conclude
that as people age, they tend to spend more money eating out.
Is there any potential bias in this study?
A) Yes, because the age group selected does not represent the entire
population
B) Yes, because they should also include people that do not eat out in
the study
C) No, because people in that age group are more likely to afford
eating out
D) No, because the sample is representative of the population
Answer: Yes, because the age group selected does not represent the
entire population
, ◉ A medical research group studying pulmonary health is working
on two major studies.
First study: In an attempt to study the health effects of coal dust, the
group selected 4,000 subjects from four communities, two of which
are home to large proportions of coal miners. The researchers
followed the health of the subjects over a 12-year period.
Second study: In an attempt to study interactions between
environmental cigarette smoke and childhood asthma, the group
selected 145 asthmatic children and their parents. The researchers
followed the children's health and the smoking habits of the parents
for five years.
What is true regarding the two studies?
A) Both studies are observational.
B) Study 1 is observational; study 2 is experimental.
C) Study 1 is experimental; study 2 is observational.
D) Both studies are experimental.
Answer: Both studies are observational.
◉ A researcher studying the effects of chocolate on learning selects
six groups of 20 mice each at random from a laboratory population.
STATISTICS CORE REVIEW SHEET 2026
DESCRIPTIVE STATISTICS AND DATA
INTERPRETATION SKILLS
◉ A study is being conducted on the relationship between age and
the amount of money people spend on eating out. Researchers
gather data from a group of 100 people ages 50 to 65 and conclude
that as people age, they tend to spend more money eating out.
Is there any potential bias in this study?
A) Yes, because the age group selected does not represent the entire
population
B) Yes, because they should also include people that do not eat out in
the study
C) No, because people in that age group are more likely to afford
eating out
D) No, because the sample is representative of the population
Answer: Yes, because the age group selected does not represent the
entire population
, ◉ A medical research group studying pulmonary health is working
on two major studies.
First study: In an attempt to study the health effects of coal dust, the
group selected 4,000 subjects from four communities, two of which
are home to large proportions of coal miners. The researchers
followed the health of the subjects over a 12-year period.
Second study: In an attempt to study interactions between
environmental cigarette smoke and childhood asthma, the group
selected 145 asthmatic children and their parents. The researchers
followed the children's health and the smoking habits of the parents
for five years.
What is true regarding the two studies?
A) Both studies are observational.
B) Study 1 is observational; study 2 is experimental.
C) Study 1 is experimental; study 2 is observational.
D) Both studies are experimental.
Answer: Both studies are observational.
◉ A researcher studying the effects of chocolate on learning selects
six groups of 20 mice each at random from a laboratory population.
