Question 185842
1 If a court acquits every defendant, they will never commit a Type I error.
Type I is the probability you reject Ho when it is true.
Ho for court proceedings is "the defendent is innocent"
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Acquittal means the court accepts Ho.  So the answer is True
A) 
True
B) 
False
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2 The probability of rejecting a true null hypothesis increases as the sample size increases.
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As n increases the test statistic value [z*(s/sqrt(n)] will decrease
increasing the p-value and decreasing the chance of rejecting Ho.
Ans: False

A) 
True

B) 
False
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3 For a given level of significance, the critical value of Student's t increases as n increases.
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The critical value does not depend on the size of "n".
Ans: False

A) 
True

B) 
False
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4 In a two-tailed hypothesis test with α = .05, a test statistic of t = 1.813 with d.f. = 15 leads one to reject the null hypothesis of a statistical test.
Ans: False

A) 
True

B) 
False
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5 The power of a test is the probability that the test will reject a false null hypothesis.
Ans: True

A) 
True

B) 
False
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6 The height of the power curve shows the probability of accepting a true null hypothesis
Ans: False

A) 
True

B) 
False
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7 Which is not true of p-values?

A) 
When they are small, we want to reject Ho.
True
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B) 
They must be specified before the sample is taken.
False
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C) 
They show the chance of Type I error if we reject Ho.
False


D) 
They do not require α to be specified a priori.
True
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Use the following scenario to answer questions 8 to 10.
Dullco Manufacturing claims that its alkaline batteries last forty hours on average in a certain type of portable CD player. Tests on a random sample of 18 batteries showed a mean battery life of 37.8 hours with a standard deviation of 5.4 hours.

8 The test statistic is
t(37.8) = (37.8-40)/[5.4/sqrt(18)] = -1.7285

A) 
-1.980

B) 
-1.728

C) 
-2.101

D) 
-1.960
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9 In determining the p-value for reporting the study's findings, which of the following is true?
Ans: The p-value cannot be determined unless you know whether the
test is two-tail, left, or right.  Similarly the rest of the questions
under 9 cannot be answered.
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A) 
The p-value is less than .05.

B) 
The p-value is equal to .05.

C) 
The p-value is greater than .05.

D) 
The p-value cannot be determined without specifying α.

10 In a left-tailed test at α = .05 we would

A) 
comfortably reject the claim.

B) 
comfortably accept the claim.

C) 
feel uncomfortable with either decision (too close).

D) 
switch to alpha of 0.01 for a more powerful test.
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Cheers,
Stan H.