1. Compare
Sophomores and Freshmen – is either group more responsible about doing
homework than the other? To
address this issue, data was collected for two courses that are taken by
both Sophomores and Freshmen. The
instructors of those courses reported whether or not each student had completed
all homework assignments.The data
are tabulated below.
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(a) Suppose
you were writing an article about this study. Write
a couple of sentences in which you are reporting some basic descriptive
statistics that summarize the results.
(b) Now
do the inferential statistical analysis, using the Chi-Square test. State
the hypotheses in words.
H0:
HA:
Figure
out the Expected cell counts and put these into the table below.
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Calculate
the Chi-Square test statistic.
Give
a range for the P-value.
State
a conclusion.
2. Your
conclusion has been challenged! Critics
charge that you neglected to take into account that there may be differences
between these two courses. If
separate tallies are made for each course, the results look like this:
Course:Art
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Course:Calculus
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(a) Summarize
the results for the Art course. (Report
the key descriptive statistics.)
(b) Summarize
the results for the Calculus course. (Report the key descriptive
statistics.)
(c) Hey,
what a minute! These summaries
(Parts a & b) conflict with your results for the combined data (Question
1). Can you give some logical
explanation of this apparent paradox?
(d) What
should be concluded regarding the original research question posed in the
first sentence of #1?
(e) Do
the Chi-Square test for the Art course data.
(f)
Do the Chi-Square test for the Calculus course data.