WGU C955 APPLIED PROBABILITY AND STATISTICS EXAM
BRAND NEW VERSION 2027-2028 Q&A EXAM -PRACTICE
QUESTIONS AND ANSWERS PLUS DETAILED RATIONALES |
COMPLETE STUDYGUIDE| GUARANTEED PASS | DOWNLOAD
INSTANT PDF 2027-2028
1. A retail manager records the number of items purchased by each customer during a one-
hour period. Which measure of center is most appropriate if a few customers purchase
unusually large quantities?
A. Mean
B. Median
C. Range
D. Standard deviation
The median is resistant to extreme values, so it provides a more representative measure of
center when unusually large purchases create skewness.
2. A dataset contains the values 4, 6, 8, 10, and 12. What is the arithmetic mean?
A. 6
B. 7
C. 8
D. 10
The mean is found by adding the observations and dividing by the number of observations: (4
+ 6 + 8 + 10 + 12) / 5 = 8.
3. A quality-control analyst wants to describe how spread out production measurements
are around their mean. Which statistic directly measures average squared deviation from
the mean?
A. Variance
B. Median
C. Mode
D. Percentile
Variance measures the average squared distance of observations from the mean and is a
fundamental measure of statistical dispersion.
,4. A company reports that the average delivery time is 42 minutes with a standard
deviation of 5 minutes. What does the standard deviation indicate?
A. The most common delivery takes exactly 5 minutes.
B. The median delivery time is 5 minutes below the mean.
C. Every delivery differs from 42 minutes by exactly 5 minutes.
D. Delivery times typically vary from the mean by about 5 minutes.
Standard deviation describes the typical amount of variation around the mean. It does not
mean every observation differs by exactly that amount.
5. An analyst ranks employee salaries from lowest to highest and wants the value
separating the lowest 75% of salaries from the highest 25%. Which statistic should be
used?
A. First quartile
B. Third quartile
C. Median
D. Range
The third quartile, Q3, is the 75th percentile and separates approximately the lower 75% of
observations from the upper 25%.
6. A probability distribution assigns probabilities of 0.20, 0.35, 0.25, and 0.20 to four
possible outcomes. What must be true of this distribution?
A. The probabilities are invalid because they are not all equal.
B. The distribution must be continuous.
C. The probabilities form a valid discrete probability distribution.
D. The expected value must equal 1.
The probabilities are nonnegative and sum to 1.00, satisfying the basic requirements of a
discrete probability distribution.
7. A six-sided die is rolled once. What is the probability of obtaining a 4?
A. 1/6
B. 1/4
, C. 1/3
D. 4/6
A fair six-sided die has six equally likely outcomes, and only one outcome is a 4, giving a
probability of 1/6.
8. A warehouse randomly selects one of 20 shipments for inspection. Five shipments are
classified as priority shipments. What is the probability that the selected shipment is a
priority shipment?
A. 0.05
B. 0.10
C. 0.20
D. 0.25
The probability is favorable outcomes divided by total outcomes: 5/20 = 0.25.
9. A customer-support center finds that 70% of customers use online support and 30% use
telephone support. If one customer is selected at random, what is the probability the
customer uses either method?
A. 0.30
B. 0.70
C. 1.00
D. 0.40
Because the two methods represent all customers in this simplified scenario, their
probabilities sum to 1.00.
10. A fair coin is tossed three times. What is the probability of getting heads on all three
tosses?
A. 1/8
B. 1/6
C. 1/4
D. 3/8
The tosses are independent, so the probability is (1/2)(1/2)(1/2) = 1/8.
BRAND NEW VERSION 2027-2028 Q&A EXAM -PRACTICE
QUESTIONS AND ANSWERS PLUS DETAILED RATIONALES |
COMPLETE STUDYGUIDE| GUARANTEED PASS | DOWNLOAD
INSTANT PDF 2027-2028
1. A retail manager records the number of items purchased by each customer during a one-
hour period. Which measure of center is most appropriate if a few customers purchase
unusually large quantities?
A. Mean
B. Median
C. Range
D. Standard deviation
The median is resistant to extreme values, so it provides a more representative measure of
center when unusually large purchases create skewness.
2. A dataset contains the values 4, 6, 8, 10, and 12. What is the arithmetic mean?
A. 6
B. 7
C. 8
D. 10
The mean is found by adding the observations and dividing by the number of observations: (4
+ 6 + 8 + 10 + 12) / 5 = 8.
3. A quality-control analyst wants to describe how spread out production measurements
are around their mean. Which statistic directly measures average squared deviation from
the mean?
A. Variance
B. Median
C. Mode
D. Percentile
Variance measures the average squared distance of observations from the mean and is a
fundamental measure of statistical dispersion.
,4. A company reports that the average delivery time is 42 minutes with a standard
deviation of 5 minutes. What does the standard deviation indicate?
A. The most common delivery takes exactly 5 minutes.
B. The median delivery time is 5 minutes below the mean.
C. Every delivery differs from 42 minutes by exactly 5 minutes.
D. Delivery times typically vary from the mean by about 5 minutes.
Standard deviation describes the typical amount of variation around the mean. It does not
mean every observation differs by exactly that amount.
5. An analyst ranks employee salaries from lowest to highest and wants the value
separating the lowest 75% of salaries from the highest 25%. Which statistic should be
used?
A. First quartile
B. Third quartile
C. Median
D. Range
The third quartile, Q3, is the 75th percentile and separates approximately the lower 75% of
observations from the upper 25%.
6. A probability distribution assigns probabilities of 0.20, 0.35, 0.25, and 0.20 to four
possible outcomes. What must be true of this distribution?
A. The probabilities are invalid because they are not all equal.
B. The distribution must be continuous.
C. The probabilities form a valid discrete probability distribution.
D. The expected value must equal 1.
The probabilities are nonnegative and sum to 1.00, satisfying the basic requirements of a
discrete probability distribution.
7. A six-sided die is rolled once. What is the probability of obtaining a 4?
A. 1/6
B. 1/4
, C. 1/3
D. 4/6
A fair six-sided die has six equally likely outcomes, and only one outcome is a 4, giving a
probability of 1/6.
8. A warehouse randomly selects one of 20 shipments for inspection. Five shipments are
classified as priority shipments. What is the probability that the selected shipment is a
priority shipment?
A. 0.05
B. 0.10
C. 0.20
D. 0.25
The probability is favorable outcomes divided by total outcomes: 5/20 = 0.25.
9. A customer-support center finds that 70% of customers use online support and 30% use
telephone support. If one customer is selected at random, what is the probability the
customer uses either method?
A. 0.30
B. 0.70
C. 1.00
D. 0.40
Because the two methods represent all customers in this simplified scenario, their
probabilities sum to 1.00.
10. A fair coin is tossed three times. What is the probability of getting heads on all three
tosses?
A. 1/8
B. 1/6
C. 1/4
D. 3/8
The tosses are independent, so the probability is (1/2)(1/2)(1/2) = 1/8.
