1			If a researcher is testing the difference in population mean before and after some experimental intervention, the use of the ___________ test will reduce the ___________ error rate without a corresponding increase in the risk of an inappropriately rejected null hypothesis.
			A)	Paired-observation t; Type I
			B)	Paired-observation t; Type II
			C)	Independent-samples z; Type I
			D)	Independent-samples z; Type II
			E)	None of the above

Use the following to answer questions 2-4:

A tire manufacturer claims that his tires last at least 1,500 miles more than his competitor's. Two independent samples of 10 tires each are subjected to wear and the average life of the company's tires is found to be 16,700 miles, with a standard deviation of 1,700 miles. The competitor's tires last a mean of 15,100 miles, with a standard deviation of 1,350 miles.

2			State the null hypothesis to test whether the manufacturer's claim is true. Assume that the manufacturer's tires are population 1 and the competitor's tires are population 2.
			A)	H0: μ1 - μ 2 ≥ 1,500
			B)	H0: μ1 - μ 2 ≥ 0
			C)	H0: μ1 - μ 2 ≤ 1,500
			D)	H0: μ1 - μ 2 ≤ 0
			E)	H0: μ1 - μ 2 = 1,500
3			Find the critical value or values to test the claim that the manufacturer's tires last on the average at least 1,500 more miles that the competitor's tires. Use α = 0.05.
			A)	1.330
			B)	1.734
			C)	1.645
			D)	2.101
			E)	1.96
4			Compute the test statistic for this test.
			A)	2.33
			B)	9.16
			C)	1.53
			D)	0.146
			E)	none of the above

Use the following to answer questions 5-7:

The rate of consumption of disposable tooling is a significant cost driver at a small manufacturing firm which employs 12 workers. Recently, on a trial basis the firm switched suppliers of its tooling and observed the following changes in rates of consumption across its employees:

Employee	Monthly Consumption
	Old	New
Charles	72	59
Caroline	59	57
Emma	44	37
Andrew	51	51
Roy	91	66
Colleen	73	63
Edgar	55	60
Gregory	80	72
Janet	72	67
Brenda	57	48
Susan	62	53
Michael	65	67

The firm will permanently switch suppliers only if it has substantial evidence (α = 0.05) that consumption is lower under the new supplier.

5			What are the most appropriate null and alternate hypotheses for this scenario?
			A)	H0: μ1 − μ2 ≤ 0; H1: μ1 − μ2 > 0
			B)	H0: μ1 − μ2 = 0; H1: μ1 − μ2 ≠ 0
			C)	H0: μD ≤ 0; H1: μD < 0
			D)	H0: μD ≥ 0; H1: μD < 0
			E)	H0: μD = 0; H1: μD ≠ 0
6			What is an appropriate decision rule to use for hypothesis testing in this situation?
			A)	Reject H0 if the observed t is less than -1.796
			B)	Reject H0 if the absolute value of the observed t is greater than 2.074
			C)	Reject H0 if the observed t is less than -2.200
			D)	Reject H0 if the absolute value of the observed z is greater than 1.96
			E)	Reject H0 if the absolute value of the observed z is less than -1.645
7			Compute the test statistic for this test:
			A)	t = -2.97
			B)	t = -1.42
			C)	t = -0.38
			D)	z = -0.96
			E)	z = -1.37

Use the following to answer questions 8-10:

A manufacturing firm uses two different processes to evaluate the quality of incoming components of a particular class. In a recent test of the processes' effectiveness, a random sample was taken consisting of 5,000 components, 2,500 that had been evaluated by process A and 2,500 that had been evaluated by process B. Of the 2,500 that had been evaluated by process A, 87 had been misclassified. Process B generated 65 misclassifications in its sample. Assume that this evaluation was undertaken to determine if there is sufficient evidence to conclude that process B leads to a lower miscalculation rate. Assume also that α is set at 0.05.

8			Which of the following is the appropriate null hypothesis to test in this instance?
			A)	H0: pA - pB ≤ 0
			B)	H0: pA - pB ≥ 0
			C)	H0: pA - pB = 0
			D)	H0: pA − pB ≠ 0
			E)	None of the above
9			What is the appropriate critical value for the test statistic in this instance?
			A)	Z < - 1.96
			B)	Z < - 1.645
			C)	Z > 2.33
			D)	Z > 1.96
			E)	Z > 1.645
10			What is the p-value for the observed test statistic in this instance?
			A)	0.0351
			B)	0.0708
			C)	0.1401
			D)	0.3085
			E)	0.2266
11			When conducting hypothesis tests regarding the differences in means across two populations, an important assumption typically is that:
			A)	The populations are not normally distributed
			B)	The populations have equivalent correlations
			C)	The populations have similar p-values
			D)	The populations have similar means
			E)	None of the above
12			In a test comparing two population means drawn from independent samples, the 8 observations from population 1 had a sample standard deviation of 3.15 and the 11 observations from population 2 had a sample standard deviation of 2.98. Assuming σ1 and σ2 are equal, an estimate for the common population variance would be:
			A)	Not in excess of 3
			B)	In excess of 3 but not in excess of 5
			C)	In excess of 5 but not in excess of 7
			D)	In excess of 7 but not in excess of 9
			E)	In excess of 9