Appendix C Closure (Review)
CL C-60. Jet Set claims that they are more “on time” than National Airways because National was delayed over an hour a couple
times. Arin did not believe Jet Set was more “on time” so he looked up the data for both airlines during the last two weeks. Below is
the data he found for departure delays. Negative numbers indicate that a flight departed earlier than scheduled.
a) Compare the center, shape, spread, and outliers of the data sets. Use the values you calculate to make an argument as to which
airline is on time more often. Use a bin width of 10 minutes on your histograms.
b) Arin wants to summarize his findings with just two numbers: the center and spread. Can he use mean and standard deviation, or
should he use median and IQR? Justify your choice, then summarize the data for Arin.
CL C-61. Given the system of equations:
a) How many points of intersection should there be?
b) Use your algebra skills to verify the answer to (a) and find the exact coordinates of the point(s) of intersection.
CL C-62. For the parabola: y = 2x2 − 12x + 6
a) Is the vertex is a maximum or minimum? Explain your reasoning.
b) Determine the coordinates of the vertex.
c) Make a sketch of the graph without using a calculator.
CL C-63. Without graphing, determine all of the points of intersections of these two equations.
CL C-64. Check your answers using the key. Which problems do you feel confident about? Which problems were hard? Use the
table to make a list of topics you need help on and a list of topics you need to practice more.
Answers and Support for Appendix C Closure
Note: MN = Math Note, LL = Learning Log
Problem
Solutions
CL C60.
Need Help?
More Practice
Lesson C.1.2
Problems C-26, C-35, C-44,C-51,
MN: C.1.2 and C.1.3 and C-52
LL: C.1.2
a. Median delay for Jet Set is about 16 minutes longer than for
National. National’s delays were skewed with a peak at about –5
minutes, meaning they had a lot of flights that left early or had
only a little delay, while Jet Set’s delays were uniformly
distributed. Jet Set had more variability in delays than National
did; the IQR for Jet Set’s delays was 6 minutes wider than for
National’s IQR. National did have two extreme outliers. Even
though National had two very large delays in the last couple
weeks, their overall performance makes them more “on time”
than Jet Set. Jet Set’s claims are misleading because they
focused only on the outliers rather than on overall performance.
b. Although the distribution for Jet Set is symmetric with no
outliers, National is skewed with outliers. Since he wants to
compare data, he needs to use the same statistics for both
airlines. Arin must use median and IQR. Median delay for
National is 1 minute with an IQR of 21 minutes, while Jet Set
has median delay if 17 minutes with an IQR of 27 minutes.
CL C61.
a. 2
b. (−2, 0), (−4, 4)
CL C62.
Chapter 4
Problem C-43
Chapter 2
Problems C-19, C-29, andC-53
Chapter 4
Problem C-54
a. Parabola opens up so the vertex
is a minimum.
b. (3, 12)
c. See graph at right.
CL C63.
(−3, 8) and (1, −12)