STATS 210 FINAL EXAM STUDY GUIDE 2026/2027 | PRACTICE QUESTIONS,
VERIFIED ANSWERS & COMPREHENSIVE REVIEW
Exhibit 1, Question 1: Based solely on the graph, could you say eating breakfast and student
performance have a cause-and-effect relationship? Explain. - correct answer ✔✔No. From the
graph we only know they are associated and association does not imply causation.
Exhibit 2, Question 1: Reportedly, the Legislature was told that this graph shows that global
warming is good because it causes a decrease in infant mortality. Is this an accurate
assessment? Explain. - correct answer ✔✔That is really not a correct explanation. The graph
shows only correlation, not causation. Probably it is how industrialized the nation is that affects
both carbon footprint and infant mortality. Certainly it is not saying that a large carbon footprint
is directly responsible for a reduction in infant mortality.
Exhibit 1, Question 2: Does the scatterplot show a positive association or a negative association,
and how do you know? - correct answer ✔✔Association is negative (because scatterplot is
downwards to the right).
Exhibit 1, Question 3: Is the association weak or strong, and how do you know? - correct answer
✔✔Pretty strong. Points are pretty tightly packed about the curvy trend we see in the plot.
Exhibit 2, Question 1: Redo the scatterplot from Exhibit 1. Same rules as before: use a computer
package and submit professional-level results. This time, plot log10 (Child Mortality) versus
log10 (CO2 Emissions). How does this plot compare to the one you did in Exhibit 1? - correct
answer ✔✔This one is much more in the shape of a straight line than the original one from
Exhibit 1.
Exhibit 2, Question 2: Does the new scatterplot show a positive association or a negative
association, and how do you know? - correct answer ✔✔Association is negative (because
scatterplot is downwards to the right).
,Exhibit 1, Question 1: What is the value of r? - correct answer ✔✔r = -0.44
Exhibit 1, Question 3: Do you think the computation of r is appropriate for these data? Why or
why not? - correct answer ✔✔Probably not. That plot was not a straight-line plot so r might be
deceptive here.
Exhibit 2, Question 1: What is the value of r? - correct answer ✔✔r=-0.80
Do you think the computation of r is appropriate for these data? Why or why not? (You
constructed a scatterplot of these data in Beyond the Numbers 1.27.) - correct answer
✔✔Makes much more sense for these data since the transformed plot looked much more like a
straight
line.
A plot very similar to the one shown here was allegedly presented to the Kentucky House of
Representatives as part of an overall message that related CO2 emissions to child mortality.
How did taking log base 10 of each variable shown, and making a new plot, make using "r" more
reasonable for measuring association? - correct answer ✔✔The transformed scatterplot went
from showing a curved trend to showing a straight line trend.
In Excel what is the function for finding the correlation coefficient? Google on this if you don't
know. - correct answer ✔✔=CORREL( )
We looked at a study that showed college students who ate breakfast had a higher success rate
on General Biology exams than those students who did not eat breakfast. The operative graph is
repeated below. What does the graph tell you? - correct answer ✔✔Eating breakfast is
associated with better class performance.
We looked at a study that showed college students who ate breakfast had a higher success rate
on General Biology exams than those students who did not eat breakfast. The operative graph is
repeated below. The study was done on 1,259 college students, 825 of whom self-identified as
, having eaten breakfast before taking the exam. What can you say about the number of students
who got D's and E's in each of the two groups? - correct answer ✔✔The Breakfast group had
more D's and E's
Suppose we have data like in Problem 4 that can be into a so-called 2x2 table like you see below.
The letters U, V, W, X just stand for the counts that are in those cells. What is the probability of
getting a Grade of C or Better if you ate breakfast, divided by the probability of getting a Grade
Below C if you ate breakfast? - correct answer ✔✔U/V
The correlation coefficient is always: - correct answer ✔✔Between -1 and 1
Two variables measured on the same individual are ASSOCIATED if: - correct answer ✔✔If some
values of one of the variables tend to occur more often with certain values of the second
variable than with other values of that variable
If you compute a correlation coefficient to be -0.26 what does that tell you about the
scatterplot, all things being equal? - correct answer ✔✔Should be a recognizable, though not
strong, downward to the right trend
A plot very similar to the one shown here was allegedly presented to the Kentucky House of
Representatives as part of an overall message that CO2 emissions are negatively associated with
child mortality rates. What would you say in response to this argument? - correct answer
✔✔It's reasonable; low C02 emissions are somewhat paired with high mortality rates.
A plot very similar to the one shown here was allegedly presented to the Kentucky House of
Representatives as part of an overall message that an increase in CO2 emissions causes a
decrease in child mortality rates. What would you say in response to this argument? - correct
answer ✔✔It's irrational; the pairing of high C02 emissions with low mortality rates only shows
an association. There is no evidence of direct cause and effect.
What is a "quasi experiment"? - correct answer ✔✔Experiments unable to use randomization to
evaluate treatment effectiveness.
VERIFIED ANSWERS & COMPREHENSIVE REVIEW
Exhibit 1, Question 1: Based solely on the graph, could you say eating breakfast and student
performance have a cause-and-effect relationship? Explain. - correct answer ✔✔No. From the
graph we only know they are associated and association does not imply causation.
Exhibit 2, Question 1: Reportedly, the Legislature was told that this graph shows that global
warming is good because it causes a decrease in infant mortality. Is this an accurate
assessment? Explain. - correct answer ✔✔That is really not a correct explanation. The graph
shows only correlation, not causation. Probably it is how industrialized the nation is that affects
both carbon footprint and infant mortality. Certainly it is not saying that a large carbon footprint
is directly responsible for a reduction in infant mortality.
Exhibit 1, Question 2: Does the scatterplot show a positive association or a negative association,
and how do you know? - correct answer ✔✔Association is negative (because scatterplot is
downwards to the right).
Exhibit 1, Question 3: Is the association weak or strong, and how do you know? - correct answer
✔✔Pretty strong. Points are pretty tightly packed about the curvy trend we see in the plot.
Exhibit 2, Question 1: Redo the scatterplot from Exhibit 1. Same rules as before: use a computer
package and submit professional-level results. This time, plot log10 (Child Mortality) versus
log10 (CO2 Emissions). How does this plot compare to the one you did in Exhibit 1? - correct
answer ✔✔This one is much more in the shape of a straight line than the original one from
Exhibit 1.
Exhibit 2, Question 2: Does the new scatterplot show a positive association or a negative
association, and how do you know? - correct answer ✔✔Association is negative (because
scatterplot is downwards to the right).
,Exhibit 1, Question 1: What is the value of r? - correct answer ✔✔r = -0.44
Exhibit 1, Question 3: Do you think the computation of r is appropriate for these data? Why or
why not? - correct answer ✔✔Probably not. That plot was not a straight-line plot so r might be
deceptive here.
Exhibit 2, Question 1: What is the value of r? - correct answer ✔✔r=-0.80
Do you think the computation of r is appropriate for these data? Why or why not? (You
constructed a scatterplot of these data in Beyond the Numbers 1.27.) - correct answer
✔✔Makes much more sense for these data since the transformed plot looked much more like a
straight
line.
A plot very similar to the one shown here was allegedly presented to the Kentucky House of
Representatives as part of an overall message that related CO2 emissions to child mortality.
How did taking log base 10 of each variable shown, and making a new plot, make using "r" more
reasonable for measuring association? - correct answer ✔✔The transformed scatterplot went
from showing a curved trend to showing a straight line trend.
In Excel what is the function for finding the correlation coefficient? Google on this if you don't
know. - correct answer ✔✔=CORREL( )
We looked at a study that showed college students who ate breakfast had a higher success rate
on General Biology exams than those students who did not eat breakfast. The operative graph is
repeated below. What does the graph tell you? - correct answer ✔✔Eating breakfast is
associated with better class performance.
We looked at a study that showed college students who ate breakfast had a higher success rate
on General Biology exams than those students who did not eat breakfast. The operative graph is
repeated below. The study was done on 1,259 college students, 825 of whom self-identified as
, having eaten breakfast before taking the exam. What can you say about the number of students
who got D's and E's in each of the two groups? - correct answer ✔✔The Breakfast group had
more D's and E's
Suppose we have data like in Problem 4 that can be into a so-called 2x2 table like you see below.
The letters U, V, W, X just stand for the counts that are in those cells. What is the probability of
getting a Grade of C or Better if you ate breakfast, divided by the probability of getting a Grade
Below C if you ate breakfast? - correct answer ✔✔U/V
The correlation coefficient is always: - correct answer ✔✔Between -1 and 1
Two variables measured on the same individual are ASSOCIATED if: - correct answer ✔✔If some
values of one of the variables tend to occur more often with certain values of the second
variable than with other values of that variable
If you compute a correlation coefficient to be -0.26 what does that tell you about the
scatterplot, all things being equal? - correct answer ✔✔Should be a recognizable, though not
strong, downward to the right trend
A plot very similar to the one shown here was allegedly presented to the Kentucky House of
Representatives as part of an overall message that CO2 emissions are negatively associated with
child mortality rates. What would you say in response to this argument? - correct answer
✔✔It's reasonable; low C02 emissions are somewhat paired with high mortality rates.
A plot very similar to the one shown here was allegedly presented to the Kentucky House of
Representatives as part of an overall message that an increase in CO2 emissions causes a
decrease in child mortality rates. What would you say in response to this argument? - correct
answer ✔✔It's irrational; the pairing of high C02 emissions with low mortality rates only shows
an association. There is no evidence of direct cause and effect.
What is a "quasi experiment"? - correct answer ✔✔Experiments unable to use randomization to
evaluate treatment effectiveness.
