QMB 3200 STUDY GUIDE EXAM 2026
QUESTIONS WITH SOLUTIONS GRADED A+
◉ Which of the following is not resistant to the outliers in a data set?
a. Median
b. Mean
c. Variance
d. Interquartile range. Answer: b. mean
◉ The pth percentile is a value such that at least p percent of the
observations are: Answer: less than or equal to this value.
◉ Which of the following provides a measure of central location for the
data?
a. Mean
b. Variance
c. Mode
d. Standard deviation. Answer: a. mean
◉ When testing water for chemical impurities, results are often reported
as BDL, that is, below detection limit. The following data set gives the
,measurements of the amount of lead in a series of water samples taken
from inner-city households (ppm):
5, 7, 12, BDL, 10, 8, BDL, 20, 6
Which of the following is correct?
a. The mean lead level in the water is about 10 ppm.
b. The median lead level in the water is 8 ppm.
c. The mean lead level in the water is about 8 ppm.
d. The median lead level in the water is 7 ppm: Answer: d. The median
lead level in the water is 7 ppm.
◉ A student made scores of 85, 56, and 91 on her first three statistics
tests. What score does she need to make on her next test to have an 80
test average? Answer: 88
◉ Growth factors for the population of Dallas in the past five years have
been 1, 2, 3, 4, and 5, respectively. The geometric mean is: Answer:
^5square root 120
◉ A sample of 99 distances has a mean of 24 feet and a median of 21.5
feet. Unfortunately, it has just been discovered that an observation that
was erroneously recorded as "30" actually had a value of "35." If we
make this correction to the data, then: Answer: the median remains the
same, but the mean is increased.
, ◉ A numerical value used as a summary measure for a sample, such as
sample mean, is known as a: Answer: sample statistic.
◉ The measure of location that is most likely to be influenced by
extreme values in a data set is the: Answer: mean
◉ A student was performing an experiment that compared a new high
protein food to the old food for pigs. He found the mean weight gain for
subjects consuming the new food to be 12.8 pounds with a standard
deviation of 3.5 pounds. Later, he realized that the scale was out of
calibration by 1.5 pounds (meaning that the scale weighed items 1.5
pounds more). What should be the summary measures, mean and
standard deviation, for the subjects consuming the new food? Answer:
The mean should be 11.3 and the standard deviation should remain
unchanged.
◉ When a set of data has suspect outliers, which of the following is the
referred measure of central tendency? Answer: median
◉ In a sample of 500 students whose mean height is 67.8 inches, 150
were women. If the mean height of the women was 63.0 inches, what is
the mean height of the men in the sample? Answer: 69.9
◉ The coefficient of variation formula. Answer: the standard deviation
divided by the mean and multiplied by 100.
QUESTIONS WITH SOLUTIONS GRADED A+
◉ Which of the following is not resistant to the outliers in a data set?
a. Median
b. Mean
c. Variance
d. Interquartile range. Answer: b. mean
◉ The pth percentile is a value such that at least p percent of the
observations are: Answer: less than or equal to this value.
◉ Which of the following provides a measure of central location for the
data?
a. Mean
b. Variance
c. Mode
d. Standard deviation. Answer: a. mean
◉ When testing water for chemical impurities, results are often reported
as BDL, that is, below detection limit. The following data set gives the
,measurements of the amount of lead in a series of water samples taken
from inner-city households (ppm):
5, 7, 12, BDL, 10, 8, BDL, 20, 6
Which of the following is correct?
a. The mean lead level in the water is about 10 ppm.
b. The median lead level in the water is 8 ppm.
c. The mean lead level in the water is about 8 ppm.
d. The median lead level in the water is 7 ppm: Answer: d. The median
lead level in the water is 7 ppm.
◉ A student made scores of 85, 56, and 91 on her first three statistics
tests. What score does she need to make on her next test to have an 80
test average? Answer: 88
◉ Growth factors for the population of Dallas in the past five years have
been 1, 2, 3, 4, and 5, respectively. The geometric mean is: Answer:
^5square root 120
◉ A sample of 99 distances has a mean of 24 feet and a median of 21.5
feet. Unfortunately, it has just been discovered that an observation that
was erroneously recorded as "30" actually had a value of "35." If we
make this correction to the data, then: Answer: the median remains the
same, but the mean is increased.
, ◉ A numerical value used as a summary measure for a sample, such as
sample mean, is known as a: Answer: sample statistic.
◉ The measure of location that is most likely to be influenced by
extreme values in a data set is the: Answer: mean
◉ A student was performing an experiment that compared a new high
protein food to the old food for pigs. He found the mean weight gain for
subjects consuming the new food to be 12.8 pounds with a standard
deviation of 3.5 pounds. Later, he realized that the scale was out of
calibration by 1.5 pounds (meaning that the scale weighed items 1.5
pounds more). What should be the summary measures, mean and
standard deviation, for the subjects consuming the new food? Answer:
The mean should be 11.3 and the standard deviation should remain
unchanged.
◉ When a set of data has suspect outliers, which of the following is the
referred measure of central tendency? Answer: median
◉ In a sample of 500 students whose mean height is 67.8 inches, 150
were women. If the mean height of the women was 63.0 inches, what is
the mean height of the men in the sample? Answer: 69.9
◉ The coefficient of variation formula. Answer: the standard deviation
divided by the mean and multiplied by 100.
