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STAtistics / Mr. Hansen |
Name: _______________________________________ |
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1/9/2008 |
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Instant Feedback Quiz II
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1. |
In a linear regression
model the value of r is 0.221. We
can conclude that . . . |
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(A) If the
value of the explanatory variable increases, the true value of the response
variable will also increase. |
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(B) Approximately
22% of the variation in the response variable can be explained by variation
in the explanatory variable. |
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(C) Approximately
5% of the variation in the response variable can be explained by variation in
the explanatory variable. |
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(D) Both (A)
and (B) are true. |
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(E) Both (A)
and (C) are true. |
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2. |
Students attending HHS (Hypothetical
High School): |
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Left-handed |
Right-handed |
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large shoe |
10 |
40 |
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not large shoe |
12 |
48 |
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Refer to the two-way table
above. Are shoe size and handedness independent? |
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(A) Yes, since in each case the joint probabilities equal the product
of the marginal probabilities. |
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(B) Yes, since
in each case the conditional probabilities are equal to the joint
probabilities. |
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(C) No, since in
each case the joint probabilities equal the product of the marginal
probabilities. |
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(D) No, since in each case the conditional probabilities are equal to
the joint probabilities. |
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(E) No, since P(left-handed
| large shoe) ¹ P(left-handed) |
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3. |
The overriding purpose of
blocking in experimental design is _________________ ,
and an example of blocking carried to the greatest possible extreme is
_________________ . |
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(A) comparing blocks (e.g., male and female) with each other; fully
randomized design |
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(B) comparing blocks (e.g., male and female) with each other; matched
pairs |
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(C) reducing the standard deviation among the experimental units;
fully randomized design |
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(D) reducing the standard deviation among the experimental units;
matched pairs |
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(E) something else; convenience sample |
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4. |
A usually reliable
indicator of left skewness in a data set is that .
. . |
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(A) |
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