C207 Data-Driven Decision-Making Comprehensive
Questions
Question 1 of 23
Which measure of central tendency is the arithmetic average of all values in a data
set?
A. The mean is calculated by summing all values and dividing by the number of
values. ✓ Correct
B. The median is the value that occurs most frequently in the data set.
C. The interquartile range is the arithmetic average of the observations.
D. The mode is the midpoint after all values are arranged in order.
Explanation: The mean is obtained by adding every observation and dividing the total
by the number of observations.
Question 2 of 23
A data set contains one extremely high value. Which measure is generally least
affected by that outlier?
A. The mean, because every value contributes equally to its calculation.
B. The range, because it excludes unusually large observations.
C. The median, because it depends on the middle position of the ordered data. ✓
Correct
D. The standard deviation, because it measures only the center of the data.
Explanation: The median is based on rank and is therefore more resistant to extreme
values than the mean.
Question 3 of 23
How is the interquartile range calculated?
A. The median minus the first quartile is the interquartile range.
B. The maximum value minus the minimum value is the interquartile range.
C. The third quartile minus the first quartile is the interquartile range. ✓ Correct
D. The mean divided by the standard deviation is the interquartile range.
Explanation: The interquartile range measures the spread of the middle 50% of
observations using IQR = Q3 - Q1.
, Question 4 of 23
Approximately what percentage of observations in a normal distribution fall within
one standard deviation of the mean?
A. Approximately 95.4% of observations fall within one standard deviation.
B. Approximately 99.7% of observations fall within one standard deviation.
C. Approximately 50.0% of observations fall within one standard deviation.
D. Approximately 68.3% of observations fall within one standard deviation. ✓
Correct
Explanation: The empirical rule states that about 68.3% of normally distributed
observations lie within one standard deviation of the mean.
Question 5 of 23
Which level of measurement categorizes observations by names or labels without
implying order?
A. Ordinal measurement ranks observations but does not establish equal intervals.
B. Ratio measurement has equal intervals, a meaningful zero, and meaningful ratios.
C. Nominal measurement classifies observations into categories without ranking
them. ✓ Correct
D. Interval measurement ranks observations with equal intervals but no true zero.
Explanation: Nominal data identify categories, such as eye color or vehicle type, but
provide no meaningful ordering.
Question 6 of 23
Which statement best describes ratio-level measurement?
A. Ratio data have an order but unequal intervals between observations.
B. Ratio data consist only of labels that cannot be arranged in order.
C. Ratio data have ordered, equally spaced values and a meaningful true zero. ✓
Correct
D. Ratio data have equal intervals but cannot support meaningful multiplication or
division.
Explanation: A true zero allows ratio comparisons, while equal intervals support
addition, subtraction, multiplication, and division.
Questions
Question 1 of 23
Which measure of central tendency is the arithmetic average of all values in a data
set?
A. The mean is calculated by summing all values and dividing by the number of
values. ✓ Correct
B. The median is the value that occurs most frequently in the data set.
C. The interquartile range is the arithmetic average of the observations.
D. The mode is the midpoint after all values are arranged in order.
Explanation: The mean is obtained by adding every observation and dividing the total
by the number of observations.
Question 2 of 23
A data set contains one extremely high value. Which measure is generally least
affected by that outlier?
A. The mean, because every value contributes equally to its calculation.
B. The range, because it excludes unusually large observations.
C. The median, because it depends on the middle position of the ordered data. ✓
Correct
D. The standard deviation, because it measures only the center of the data.
Explanation: The median is based on rank and is therefore more resistant to extreme
values than the mean.
Question 3 of 23
How is the interquartile range calculated?
A. The median minus the first quartile is the interquartile range.
B. The maximum value minus the minimum value is the interquartile range.
C. The third quartile minus the first quartile is the interquartile range. ✓ Correct
D. The mean divided by the standard deviation is the interquartile range.
Explanation: The interquartile range measures the spread of the middle 50% of
observations using IQR = Q3 - Q1.
, Question 4 of 23
Approximately what percentage of observations in a normal distribution fall within
one standard deviation of the mean?
A. Approximately 95.4% of observations fall within one standard deviation.
B. Approximately 99.7% of observations fall within one standard deviation.
C. Approximately 50.0% of observations fall within one standard deviation.
D. Approximately 68.3% of observations fall within one standard deviation. ✓
Correct
Explanation: The empirical rule states that about 68.3% of normally distributed
observations lie within one standard deviation of the mean.
Question 5 of 23
Which level of measurement categorizes observations by names or labels without
implying order?
A. Ordinal measurement ranks observations but does not establish equal intervals.
B. Ratio measurement has equal intervals, a meaningful zero, and meaningful ratios.
C. Nominal measurement classifies observations into categories without ranking
them. ✓ Correct
D. Interval measurement ranks observations with equal intervals but no true zero.
Explanation: Nominal data identify categories, such as eye color or vehicle type, but
provide no meaningful ordering.
Question 6 of 23
Which statement best describes ratio-level measurement?
A. Ratio data have an order but unequal intervals between observations.
B. Ratio data consist only of labels that cannot be arranged in order.
C. Ratio data have ordered, equally spaced values and a meaningful true zero. ✓
Correct
D. Ratio data have equal intervals but cannot support meaningful multiplication or
division.
Explanation: A true zero allows ratio comparisons, while equal intervals support
addition, subtraction, multiplication, and division.
