428 Statistical Methods
g. Save your changes to the workbook
and write a report summarizing your
results.- The Honda12 workbook contains a sub-
set of the Honda workbook in which the
age variable is made categorical and has
the values 1–3, 4–5, and 6 or more. Some
observations of the workbook have been
removed to balance the data. The vari-
able Trans indicates the transmission,
and the variable Trans Age indicates
the combination of transmission and
age class.
a. Open the Honda12 workbook from
the Chapter10 folder and save it as
Honda12 ANOVA.
b. Create a multiple histogram and box-
plot of Price versus Trans Age. Does
the constant variance assumption for
a two-way analysis of variance appear
justifi ed?
c. Create an interaction plot of Price
versus Trans and Trans Age (you will
need to create a pivot table of means
for this). Does the plot give evidence
for an interaction between the Trans
and Trans Age factors?
d. Perform a two-way analysis of vari-
ance of Price on Trans Age and Trans
(you will have to create a two-way
table using Trans Age as the row vari-
able and Trans as the column variable).
e. Save your changes to the workbook
and write a report summarizing your
observations. - At the Olympics, competitors in the 100-
meter dash go through several rounds of
races, called heats, before reaching the
fi nals. The fi rst round of heats involves
over a hundred runners from countries
all over the globe. The heats are evenly
divided among the premier runners so
that one particular heat does not have an
overabundance of top racers. You decide
to test this assumption by analyzing data
from the 1996 Summer Olympics in
Atlanta, Georgia.
a. Open the Race workbook from the
Chapter10 folder and save it as Race
Times ANOVA.
b. Create a boxplot of the race times bro-
ken down by heats. Note any large outli-
ers in the plot and then rescale the plot
to show times from 9 to 13 seconds. Is
there any reason not to believe, based
on the boxplot, that the variation of race
times is consistent between heats?
c. Perform a one-way ANOVA to test
whether the mean race times among
the 12 heats are signifi cantly different.
d. Create a pairwise means matrix of the
race times by heat.
e. Save your workbook and summarize
your conclusions. Are the race times
different between the heats? What is
the signifi cance level of the analysis
of variance?- Repeat Exercise 16, this time looking at
the reaction times among the 12 heats and
deciding whether these reaction times
vary. Write your conclusions and save
your workbook as Race Reaction ANOVA. - Another question of interest to race
observers is whether reaction times
increase as the level of competition in-
creases. Try to answer this question by
analyzing the reaction times for the
14 athletes who competed in the fi rst three
rounds of heats of the men’s 100-meter
dash at the 1996 Summer Olympics.
a. Open the Race Rounds workbook
from the Chapter10 data folder and
save it as Race Rounds ANOVA.
b. Use the Analysis ToolPak’s ANOVA:
Two-Factor Without Replication com-
mand to perform a two-way analysis
of variance on the data in the Reaction
Times worksheet. What are the two
factors in the ANOVA table?