STA 6126
Exam 2
1.
Based on responses of 1600 subjects in General Social Surveys in the mid1980s, a
95% Confidence Interval for the mean number of close friends equals (5.6, 7.2). For
each statement, circle the best response:
Correct
or
Incorrect
.
a)
If random samples of 1600 were repeatedly selected and 95% Confidence
intervals computed based on each sample, then in the long run 95% of the
intervals would contain the true mean.
Correct
or
Incorrect
?
b)
We can be 95% confident that
Y
is between 5.6 and 7.2.
Correct
or
Incorrect
?
c)
95% of respondents had between 5.6 and 7.2 close friends.
Correct
or
Incorrect
?
d)
We can be 95% confident that \mu is between 5.6 and 7.2.
Correct
or
Incorrect
?
2.
The
P
value for testing H
0
: \mu=100
vs
H
A
: \mu
≠
100 is 0.001 and
100
<
Y
. This
indicates strong evidence that (select the correct answer):
a)
\mu<100 b) \mu>100 c) \mu=100
3.
A largesample 95% confidence interval for \mu_1\mu_2 is (2.0, 7.0). The
P
value
for testing H
0
: \mu_1\mu_2=0
vs
H
A
: \mu_1\mu_2
≠
0 based on the same sample
data is (select the correct answer):
a)
above 0.05
b)
below –0.05
c)
below 0.05
d)
Need more information
4.
Researchers reporting a Ztest to test the alterntative hypothesis that the proportion of
males favoring a candidate is larger than the proportion of females favoring the
candidate (H
A
:\mu_
M
\mu_
F
> 0) give a
P
value of
0.0643. Their computed test
statistic was:
a)
0.0643
b)
1.52
c)
1.85
d)
0.9357
e)
We need more information
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View Full DocumentFor each of the following problems, give the null and alternative hypotheses (be very
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 Spring '08
 YESILCAY
 Statistics, Normal Distribution, producer, adverse event rate

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