WGU C9556 Applied Probability and
Statistics Final Exam Actual
Questions with Verified Answers Grade A+
Guarantee. 150+ Multiple Choice
Questions Modules.
WGU C955 Applied Probability and Statistics Final Exam
Module 1: Exploratory Data Analysis (Questions 1–25)
1. A dataset contains the ages of 20 participants: 22, 22, 23, 24, 25, 25, 26, 27, 29, 30, 30, 31,
32, 34, 35, 36, 40, 42, 45, 50. What is the median age?
a) 29.5
b) 30.0
c) 30.5
d) 31.0
Answer: b) 30.0
*Rationale: With 20 data points (even), the median is the average of the 10th and 11th
values. The 10th is 30, the 11th is 30. Average = 30.*
,2. Which measure of central tendency is most affected by outliers?
a) Median
b) Mode
c) Mean
d) Range
Answer: c) Mean
Rationale: The mean incorporates all values, including extreme outliers, pulling it away from
the center. The median is resistant to outliers.
3. Given the following frequency distribution: Scores 50-59 (f=2), 60-69 (f=5), 70-79 (f=8),
80-89 (f=3), 90-99 (f=2). What is the modal class?
a) 50-59
b) 60-69
c) 70-79
d) 80-89
Answer: c) 70-79
*Rationale: The modal class is the class interval with the highest frequency, which is 8 for 70-
79.*
4. A box plot shows the minimum at 10, Q1 at 20, median at 30, Q3 at 40, and maximum at
100. What does this indicate?
a) The data is symmetric
b) There is a potential outlier on the upper end
c) The interquartile range is 70
d) The mean is less than the median
,Answer: b) There is a potential outlier on the upper end
*Rationale: The upper fence is Q3 + 1.5*IQR = 40 + 1.5*20 = 70. The maximum is 100 > 70,
indicating a potential outlier.*
5. The standard deviation of a dataset is zero. This means:
a) The mean is zero
b) All data points are equal
c) The range is zero
d) The variance is negative
Answer: b) All data points are equal
Rationale: Standard deviation measures spread. If it is zero, there is no spread, meaning all
values are identical.
6. Which of the following is a measure of variability?
a) Mean
b) Mode
c) Range
d) Median
Answer: c) Range
Rationale: Range (max-min), variance, and standard deviation measure variability. Mean,
median, and mode measure central tendency.
7. In a histogram, if the tail is longer on the right side, the distribution is:
a) Symmetric
b) Negatively skewed
c) Positively skewed
, d) Bimodal
Answer: c) Positively skewed
Rationale: Positive skew (right skew) occurs when the tail extends to the right, with mean >
median.
8. The interquartile range (IQR) is calculated as:
a) Maximum – Minimum
b) Mean – Median
c) Q3 – Q1
d) Standard Deviation squared
Answer: c) Q3 – Q1
Rationale: IQR is the range of the middle 50% of the data, representing the spread between
the first and third quartiles.
9. A stem-and-leaf plot is useful because it:
a) Hides the original data values
b) Preserves the original data while showing distribution
c) Is the best method for categorical data
d) Always uses a logarithmic scale
Answer: b) Preserves the original data while showing distribution
Rationale: Unlike histograms, stem-and-leaf plots retain the actual data points while visually
displaying the shape of the distribution.
10. If the variance of a dataset is 36, what is the standard deviation?
a) 6
b) 18
Statistics Final Exam Actual
Questions with Verified Answers Grade A+
Guarantee. 150+ Multiple Choice
Questions Modules.
WGU C955 Applied Probability and Statistics Final Exam
Module 1: Exploratory Data Analysis (Questions 1–25)
1. A dataset contains the ages of 20 participants: 22, 22, 23, 24, 25, 25, 26, 27, 29, 30, 30, 31,
32, 34, 35, 36, 40, 42, 45, 50. What is the median age?
a) 29.5
b) 30.0
c) 30.5
d) 31.0
Answer: b) 30.0
*Rationale: With 20 data points (even), the median is the average of the 10th and 11th
values. The 10th is 30, the 11th is 30. Average = 30.*
,2. Which measure of central tendency is most affected by outliers?
a) Median
b) Mode
c) Mean
d) Range
Answer: c) Mean
Rationale: The mean incorporates all values, including extreme outliers, pulling it away from
the center. The median is resistant to outliers.
3. Given the following frequency distribution: Scores 50-59 (f=2), 60-69 (f=5), 70-79 (f=8),
80-89 (f=3), 90-99 (f=2). What is the modal class?
a) 50-59
b) 60-69
c) 70-79
d) 80-89
Answer: c) 70-79
*Rationale: The modal class is the class interval with the highest frequency, which is 8 for 70-
79.*
4. A box plot shows the minimum at 10, Q1 at 20, median at 30, Q3 at 40, and maximum at
100. What does this indicate?
a) The data is symmetric
b) There is a potential outlier on the upper end
c) The interquartile range is 70
d) The mean is less than the median
,Answer: b) There is a potential outlier on the upper end
*Rationale: The upper fence is Q3 + 1.5*IQR = 40 + 1.5*20 = 70. The maximum is 100 > 70,
indicating a potential outlier.*
5. The standard deviation of a dataset is zero. This means:
a) The mean is zero
b) All data points are equal
c) The range is zero
d) The variance is negative
Answer: b) All data points are equal
Rationale: Standard deviation measures spread. If it is zero, there is no spread, meaning all
values are identical.
6. Which of the following is a measure of variability?
a) Mean
b) Mode
c) Range
d) Median
Answer: c) Range
Rationale: Range (max-min), variance, and standard deviation measure variability. Mean,
median, and mode measure central tendency.
7. In a histogram, if the tail is longer on the right side, the distribution is:
a) Symmetric
b) Negatively skewed
c) Positively skewed
, d) Bimodal
Answer: c) Positively skewed
Rationale: Positive skew (right skew) occurs when the tail extends to the right, with mean >
median.
8. The interquartile range (IQR) is calculated as:
a) Maximum – Minimum
b) Mean – Median
c) Q3 – Q1
d) Standard Deviation squared
Answer: c) Q3 – Q1
Rationale: IQR is the range of the middle 50% of the data, representing the spread between
the first and third quartiles.
9. A stem-and-leaf plot is useful because it:
a) Hides the original data values
b) Preserves the original data while showing distribution
c) Is the best method for categorical data
d) Always uses a logarithmic scale
Answer: b) Preserves the original data while showing distribution
Rationale: Unlike histograms, stem-and-leaf plots retain the actual data points while visually
displaying the shape of the distribution.
10. If the variance of a dataset is 36, what is the standard deviation?
a) 6
b) 18
