UNDERSTANDING STATS PRACTICE
EXAM 2 QUESTIONS AND 100%
CORRECT ANSWERS 2024
A teacher wants to change the seating arrangement in her class in the hope that it will increase the
number of comments her students make. She first decides to see how many comments students make
with the current seating arrangement. A record of the number of comments made by 8 of her students
during one class period is shown below. She wants to summarize this data by computing the typical
number of comments made that day. Which of the measures of central tendency would be most
appropriate for summarizing this data?
a. Median
b. Mean
c. Interquartile Range
d. Mode - ANSWER a. Median
Which of the following correlation values represents the strongest linear relationship between two
quantitative variables?
a. -1.0
b. 0.90
c. -0.68
d. 0 – ANSWER a. -1.0
A set of test scores are normally distributed. Their mean is 100 and the standard deviation is 120. These
scores are converted to standard normal z-scores. What would be the mean and median of this
standardized normal distribution?
a. 50
b. 1
c. 100
d. 0 - ANSWER d. 0
, Does the size of the standard deviation of a data set depend on where the center is?
a. No, the value of the standard deviation is not affected by the value of the mean.
b. Yes, because you have to know the mean to calculate the standard deviation.
c. No, because the standard deviation is inversely related to the mean; the higher the mean, the lower
the standard deviation.
d. Yes, the higher the mean, the higher the standard deviation. - ANSWER a. No, the value of the
standard deviation is not affected by the value of the mean.
Suppose the correlation between two variables, math attitude (x) and math achievement (y) was found
to be .78. Based on this statistic, we know that the proportion of the variability seen in math
achievement that can be predicted by math attitude is:
a. 0.61
b. 1.56
c. 0.22
d. 0.78 - ANSWER a. 0.61
Which of the following numbers will be higher, the correlation between X & Y (assuming that the
correlation between X & Y is a positive value) or the proportion of the variability in Y that is explained by
X?
a. The proportion of the variance explained will be higher.
b. There is no way to tell; these two items are not related.
c. The correlation will be higher.
d. They will be the same. - ANSWER c. The correlation will be higher.
A college statistics class conducted a survey of how students spend their money. They gathered data
from a large sample of students who estimated how much money they typically spent each week in
different categories (e.g., food, entertainment, etc.). Jack wanted to predict how much students spend
on leisure activities based on how much they spend on necessities. He calculated a regression equation,
EXAM 2 QUESTIONS AND 100%
CORRECT ANSWERS 2024
A teacher wants to change the seating arrangement in her class in the hope that it will increase the
number of comments her students make. She first decides to see how many comments students make
with the current seating arrangement. A record of the number of comments made by 8 of her students
during one class period is shown below. She wants to summarize this data by computing the typical
number of comments made that day. Which of the measures of central tendency would be most
appropriate for summarizing this data?
a. Median
b. Mean
c. Interquartile Range
d. Mode - ANSWER a. Median
Which of the following correlation values represents the strongest linear relationship between two
quantitative variables?
a. -1.0
b. 0.90
c. -0.68
d. 0 – ANSWER a. -1.0
A set of test scores are normally distributed. Their mean is 100 and the standard deviation is 120. These
scores are converted to standard normal z-scores. What would be the mean and median of this
standardized normal distribution?
a. 50
b. 1
c. 100
d. 0 - ANSWER d. 0
, Does the size of the standard deviation of a data set depend on where the center is?
a. No, the value of the standard deviation is not affected by the value of the mean.
b. Yes, because you have to know the mean to calculate the standard deviation.
c. No, because the standard deviation is inversely related to the mean; the higher the mean, the lower
the standard deviation.
d. Yes, the higher the mean, the higher the standard deviation. - ANSWER a. No, the value of the
standard deviation is not affected by the value of the mean.
Suppose the correlation between two variables, math attitude (x) and math achievement (y) was found
to be .78. Based on this statistic, we know that the proportion of the variability seen in math
achievement that can be predicted by math attitude is:
a. 0.61
b. 1.56
c. 0.22
d. 0.78 - ANSWER a. 0.61
Which of the following numbers will be higher, the correlation between X & Y (assuming that the
correlation between X & Y is a positive value) or the proportion of the variability in Y that is explained by
X?
a. The proportion of the variance explained will be higher.
b. There is no way to tell; these two items are not related.
c. The correlation will be higher.
d. They will be the same. - ANSWER c. The correlation will be higher.
A college statistics class conducted a survey of how students spend their money. They gathered data
from a large sample of students who estimated how much money they typically spent each week in
different categories (e.g., food, entertainment, etc.). Jack wanted to predict how much students spend
on leisure activities based on how much they spend on necessities. He calculated a regression equation,
