WGU C784 OBJECTIVE ASSESSMENT COMPLETE EXAM
QUESTIONS WITH FULLY EXPLAINED ANSWERS
1. A patient's temperature is recorded as 98.6°F, 99.1°F, 100.2°F,
98.6°F, and 99.5°F. What is the mode of this dataset?
A. 98.6°F
B. 99.1°F
C. 99.5°F
D. 100.2°F
Answer: A - The mode is the value that appears most frequently in a
dataset. 98.6°F appears twice, while the others appear once.
2. Which measure of central tendency is most appropriate to use
when a dataset contains extreme outliers?
A. Mean
B. Median
C. Mode
D. Range
Answer: B - The median is resistant to outliers because it is the middle
value, whereas the mean is heavily influenced by extreme values.
3. A dataset has a standard deviation of 0. What does this indicate
about the data points?
A. The data points are widely spread out.
B. The data points are all identical.
C. The data points are normally distributed.
D. The data points have a skewed distribution.
Answer: B - A standard deviation of 0 means there is no variability in the
dataset; every value is exactly the same.
,4. What is the Interquartile Range (IQR) of a dataset where the first
quartile (Q1) is 25 and the third quartile (Q3) is 65?
A. 90
B. 40
C. 25
D. 45
Answer: B - The IQR is calculated as Q3 minus Q1. Therefore, 65 - 25 =
40.
5. Which graphical representation is best suited to display the five-
number summary of a dataset?
A. Histogram
B. Bar chart
C. Box plot
D. Scatter plot
Answer: C - A box plot visually represents the minimum, first quartile,
median, third quartile, and maximum (the five-number summary).
6. If a distribution is negatively skewed, which of the following
relationships between the mean and median is true?
A. Mean > Median
B. Mean < Median
C. Mean = Median
D. Mean = Mode
Answer: B - In a negatively skewed (left-skewed) distribution, the tail
pulls the mean to the left, making it smaller than the median.
7. A researcher calculates a z-score of -2.5 for a specific patient's lab
result. What does this indicate?
A. The result is 2.5 standard deviations above the mean.
, B. The result is 2.5 standard deviations below the mean.
C. The result is 2.5 times the mean.
D. The result is 2.5% of the mean.
Answer: B - A negative z-score indicates the value is below the mean,
and the absolute value represents the number of standard deviations
away from the mean.
8. According to the Empirical Rule, approximately what percentage of
data falls within two standard deviations of the mean in a normal
distribution?
A. 68%
B. 95%
C. 99.7%
D. 50%
Answer: B - The Empirical Rule states that approximately 95% of data
falls within two standard deviations of the mean in a normal
distribution.
9. Which of the following is a measure of dispersion?
A. Median
B. Mode
C. Variance
D. Percentile
Answer: C - Variance is a measure of dispersion, indicating how far the
data points are spread from the mean. Median, mode, and percentiles
are measures of position.
10. What is the primary purpose of calculating a correlation coefficient
(r)?
A. To determine causality between two variables.
QUESTIONS WITH FULLY EXPLAINED ANSWERS
1. A patient's temperature is recorded as 98.6°F, 99.1°F, 100.2°F,
98.6°F, and 99.5°F. What is the mode of this dataset?
A. 98.6°F
B. 99.1°F
C. 99.5°F
D. 100.2°F
Answer: A - The mode is the value that appears most frequently in a
dataset. 98.6°F appears twice, while the others appear once.
2. Which measure of central tendency is most appropriate to use
when a dataset contains extreme outliers?
A. Mean
B. Median
C. Mode
D. Range
Answer: B - The median is resistant to outliers because it is the middle
value, whereas the mean is heavily influenced by extreme values.
3. A dataset has a standard deviation of 0. What does this indicate
about the data points?
A. The data points are widely spread out.
B. The data points are all identical.
C. The data points are normally distributed.
D. The data points have a skewed distribution.
Answer: B - A standard deviation of 0 means there is no variability in the
dataset; every value is exactly the same.
,4. What is the Interquartile Range (IQR) of a dataset where the first
quartile (Q1) is 25 and the third quartile (Q3) is 65?
A. 90
B. 40
C. 25
D. 45
Answer: B - The IQR is calculated as Q3 minus Q1. Therefore, 65 - 25 =
40.
5. Which graphical representation is best suited to display the five-
number summary of a dataset?
A. Histogram
B. Bar chart
C. Box plot
D. Scatter plot
Answer: C - A box plot visually represents the minimum, first quartile,
median, third quartile, and maximum (the five-number summary).
6. If a distribution is negatively skewed, which of the following
relationships between the mean and median is true?
A. Mean > Median
B. Mean < Median
C. Mean = Median
D. Mean = Mode
Answer: B - In a negatively skewed (left-skewed) distribution, the tail
pulls the mean to the left, making it smaller than the median.
7. A researcher calculates a z-score of -2.5 for a specific patient's lab
result. What does this indicate?
A. The result is 2.5 standard deviations above the mean.
, B. The result is 2.5 standard deviations below the mean.
C. The result is 2.5 times the mean.
D. The result is 2.5% of the mean.
Answer: B - A negative z-score indicates the value is below the mean,
and the absolute value represents the number of standard deviations
away from the mean.
8. According to the Empirical Rule, approximately what percentage of
data falls within two standard deviations of the mean in a normal
distribution?
A. 68%
B. 95%
C. 99.7%
D. 50%
Answer: B - The Empirical Rule states that approximately 95% of data
falls within two standard deviations of the mean in a normal
distribution.
9. Which of the following is a measure of dispersion?
A. Median
B. Mode
C. Variance
D. Percentile
Answer: C - Variance is a measure of dispersion, indicating how far the
data points are spread from the mean. Median, mode, and percentiles
are measures of position.
10. What is the primary purpose of calculating a correlation coefficient
(r)?
A. To determine causality between two variables.
