WGU C955 APPLIED PROBABILITY AND
STATISTICS FINAL EXAM
QUESTIONS AND ANSWERS WITH
RATIONALES TESTED AND APPROVED
LATEST
Question 1: Evaluate: 10³
A) 10
B) 30
C) 300
D) 1,000
Answer: D) 1,000
10³ = 10 × 10 × 10 = 1,000.
Question 2: Which set of numbers is continuous?
A) Integers
B) Rational numbers
C) Real numbers
D) Whole numbers
Answer: C) Real numbers
The set of real numbers contains no gaps and is continuous along the number line.
Question 3: What is the probability of someone having a birthday in March or December?
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,A) 1/6
B) 1/4
C) 1/3
D) 1/2
Answer: A) 1/6
March has 31 days, December has 31 days. Total days = 31+31 = 62. Probability = 62/365 ≈ 1/6
Question 4: Which of the following is true about observational studies?
A) They can prove causation
B) Researchers observe relationships without affecting anything
C) They always use random assignment
D) Subjects are split into treatment and control groups
Answer: B) Researchers observe relationships without affecting anything
In observational studies, researchers measure or survey members of a sample without trying to affect them.
These studies cannot prove causation.
Question 5: What is the only way to prove causation?
A) Observational studies
B) Surveys
C) Experiments
D) Case studies
Answer: C) Experiments
Experiments account for lurking variables through random assignment, allowing researchers to establish
cause-
and-effect
relationships.
Question 6: In an experimental study, the group that does NOT receive treatment is called the:
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,A) Treatment group
B) Control group
C) Experimental group
D) Placebo group
Answer: B) Control group
The control group does not receive the treatment and serves as a baseline for comparison with the experimental
group that does receive treatment.
Question 6: A study that watches for outcomes during the study period is called:
A) Retrospective study
B) Prospective study
C) Cross-sectional study
D) Case-control study
Answer: B) Prospective study
A prospective study follows subjects over time to observe outcomes as they occur during the study period.
Question 7: A study that looks backward to assess outcomes and possible causes after the fact is called:
A) Prospective study
B) Experimental study
C) Retrospective study
D) Longitudinal study
Answer: C) Retrospective study
Retrospective studies examine past data and outcomes to identify potential causes or risk factors.
Question 8: Which of the following sampling methods tends to increase bias?
A) Simple random sample
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, B) Systematic sample
C) Stratified sample
D) Convenience sample
Answer: D) Convenience sample
Convenience samples select participants who are easy for the researcher to access, which tends to introduce
bias because the sample may not represent the population.
Question 9: In a stratified sample, you:
A) Select every 20th name from a list
B) Divide the population into groups and select a random sample from EVERY group
C) Select a few groups and include ALL members of those groups
D) Allow members to choose whether to respond
Answer: B) Divide the population into groups and select a random sample from EVERY group
Stratified sampling divides the sampling frame into groups (strata), then selects a random sample (usually
equal
size) from within every
group.
Question 10: What is the probability of drawing a red card from a standard deck of 52 playing cards?
A) 1/4
B) 1/3
C) 1/2
D) 2/3
Answer: C) 1/2
In a standard deck, there are 26 red cards (hearts and diamonds) out of 52 total cards. Therefore, the
probability
is 26/52 = 1/2.
Question 12: A coin is flipped 4 times. How many different outcomes are possible?
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STATISTICS FINAL EXAM
QUESTIONS AND ANSWERS WITH
RATIONALES TESTED AND APPROVED
LATEST
Question 1: Evaluate: 10³
A) 10
B) 30
C) 300
D) 1,000
Answer: D) 1,000
10³ = 10 × 10 × 10 = 1,000.
Question 2: Which set of numbers is continuous?
A) Integers
B) Rational numbers
C) Real numbers
D) Whole numbers
Answer: C) Real numbers
The set of real numbers contains no gaps and is continuous along the number line.
Question 3: What is the probability of someone having a birthday in March or December?
Page 1 of 71
,A) 1/6
B) 1/4
C) 1/3
D) 1/2
Answer: A) 1/6
March has 31 days, December has 31 days. Total days = 31+31 = 62. Probability = 62/365 ≈ 1/6
Question 4: Which of the following is true about observational studies?
A) They can prove causation
B) Researchers observe relationships without affecting anything
C) They always use random assignment
D) Subjects are split into treatment and control groups
Answer: B) Researchers observe relationships without affecting anything
In observational studies, researchers measure or survey members of a sample without trying to affect them.
These studies cannot prove causation.
Question 5: What is the only way to prove causation?
A) Observational studies
B) Surveys
C) Experiments
D) Case studies
Answer: C) Experiments
Experiments account for lurking variables through random assignment, allowing researchers to establish
cause-
and-effect
relationships.
Question 6: In an experimental study, the group that does NOT receive treatment is called the:
Page 2 of 71
,A) Treatment group
B) Control group
C) Experimental group
D) Placebo group
Answer: B) Control group
The control group does not receive the treatment and serves as a baseline for comparison with the experimental
group that does receive treatment.
Question 6: A study that watches for outcomes during the study period is called:
A) Retrospective study
B) Prospective study
C) Cross-sectional study
D) Case-control study
Answer: B) Prospective study
A prospective study follows subjects over time to observe outcomes as they occur during the study period.
Question 7: A study that looks backward to assess outcomes and possible causes after the fact is called:
A) Prospective study
B) Experimental study
C) Retrospective study
D) Longitudinal study
Answer: C) Retrospective study
Retrospective studies examine past data and outcomes to identify potential causes or risk factors.
Question 8: Which of the following sampling methods tends to increase bias?
A) Simple random sample
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, B) Systematic sample
C) Stratified sample
D) Convenience sample
Answer: D) Convenience sample
Convenience samples select participants who are easy for the researcher to access, which tends to introduce
bias because the sample may not represent the population.
Question 9: In a stratified sample, you:
A) Select every 20th name from a list
B) Divide the population into groups and select a random sample from EVERY group
C) Select a few groups and include ALL members of those groups
D) Allow members to choose whether to respond
Answer: B) Divide the population into groups and select a random sample from EVERY group
Stratified sampling divides the sampling frame into groups (strata), then selects a random sample (usually
equal
size) from within every
group.
Question 10: What is the probability of drawing a red card from a standard deck of 52 playing cards?
A) 1/4
B) 1/3
C) 1/2
D) 2/3
Answer: C) 1/2
In a standard deck, there are 26 red cards (hearts and diamonds) out of 52 total cards. Therefore, the
probability
is 26/52 = 1/2.
Question 12: A coin is flipped 4 times. How many different outcomes are possible?
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