1.A hypothesis regarding the weight of newborn infants at a community hospital is that the mean is 19.1 pounds. A sample of seven infants is randomly selected and their weights at birth are recorded as 18.1, 21.1, 22.1, 23.1, 21.1, 27.1, and 27.1 pounds. What are the degrees of freedom?

		19.1
		7
		26.7
		6

2. A national manufacturer of ball bearings is experimenting with two different processes for producing precision ball bearings. It is important that the diameters be as close as possible to an industry standard. The output from each process is sampled, and the average error from the industry standard is measured in millimeters. The results are presented here.

	Process A	Process B
Sample mean	2.0	3.0
Standard deviation	1.0	0.5
Sample size	12	14

The researcher is interested in determining whether there is evidence that the two processes yield different average errors. The population standard deviations are unknown but are assumed equal. What is the null hypothesis?

		H0: A > B
		H0: A B
		H0: A B
		H0: A = B

3. Assuming the population variances are known, the variance of thedistribution of differences between twoindependent population means is ________.

		the sum of the two sample sizes for each population
		the sum of the two variances of the two sampling distributions
		the sum of the two means
		the sum of the two standarddeviations of the two sampling distributions

4. Consider a two-tailed test with a level of confidence of 81.70%. The z-value is _______.

		2.00
		0.89
		2.66
		1.33

5. In an ANOVA problem involving three treatments and 19 observations per treatment, SSE = 648. The MSE for this scenario is _______.

		12
		54
		29.5
		216

6. The following is the information for a completely randomized experimental design involving four treatments, where 20 observations were recorded for each treatment for a total of 80 observations. SST = 258 (Sum of Squares Between Groups); SS Total = 1,032 (Sum of Squares Total). The computed value of F, or the test statistic, is ________.

		8.44
		0.25
		20.0
		16.0

7. We test for a hypothesized difference between two independent population means: H₀: ₁ = ₂. The population standard deviations are unknown but assumed equal. The number of observations in the first sample is 18 and 15 in the second sample. How many degrees of freedom are associated with the critical value?

		31
		33
		32
		30

8.