Unformatted text preview: rrect if
The student recognizes that part (a) does not answer the question posed and has
two or three parts of the chi-square test completely correct.
1. Part (b) is incorrect if the student says the test in (a) does not answer the question
posed. However, if the student rejects the null hypothesis in (a), a “yes” answer to
(b) could be correct.
2. If the student says, “No. We should do a chi-square test,” but doesn’t do one, this is a
3. If student uses the 1990 data as the expected counts and the 2000 data as the
observed counts and finds χ2=23.789, the student does not receive credit for parts two
or three (but can still get a P).
Part (c) is
Essentially correct if
response has a coherent description of the difference between the 1990 and 2000
distributions and gives appropriate graphs.
NOTE: If part (b) is incorrect because the student thinks that the test in (a) does
answer the question posed, but does good graphs and bases the argument in part
(c) on the graphs, part (c) can be scored as essentially correct.
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