1. Given the significance level 0.025, the F-value for the degrees of freedom, df = (7,3) is
A. 14.62.
B. 8.45.
C. 27.67.
D. 5.89.
2. Which of the following statements are true regarding the simple linear regression model yi = β0 + β1xi +εi?
A. β0 is the slope of the regression line.
B. εi is a nonrandom error.
C. yi is a value of the dependent variable (y) and xi is a value of the independent variable (x).
D. β1 is the y-intercept of the regression line.
3. The vertical distances between observed and predicted values of y are called
A. errors of prediction.
B. scatterplots.
C. methods of least squares.
D. least square lines.
4. In a hypothesis test for the population variance, the alternate hypothesis is the population variance does not equal 17.0. The significance level to be used is 0.05 and the sample size to be taken is 25. The table value(s) to use from the chi-square distribution is/are
A. 13.120 and 40.647.
B. 40.647.
C. 12.401 and 39.364.
D. 39.364.
5. With larger and larger numbers of categories in chi-square tests, the chi-square distribution takes on the shape of the _______ distribution.
A. t-
B. Poisson
C. binomial
D. normal
6. A balanced experiment requires that
A. an equal number of persons or test units receives each treatment.
B. at least two treatment groups be used.
C. at least one sample equal size is 30.
D. the number of treatments equals the number of samples.
7. A random sample of males and females involved in rear-end accidents results in the following Minitab summary:
N MEAN MEDIAN TRMEAN STDEV SEMEAN
FEMALES 33 23.91 20.00 23.38 9.77 1.70
MALES 38 28.87 28.50 28.44 9.67 1.57
What is the standard error of the statistic between the two means?
A. 2.314
B. 1.635
C. 0.897
D. 4.96
8. A regression analysis between sales (in $1000) and advertising (in $) resulted in the following least squares line: yˆ = 80,000 + 5x. This implies that an increase of _______ in advertising is expected to resultin an increase of _______ in sales.
A. $1, $5,000
B. $1, $80,005
C. $1, $5
D. $5, $5,000
9. The F-statistic in a one-way ANOVA represents the variation
A. within the treatments minus the variation between the treatments.
B. within the treatments divided by the variation between the treatments.
C. between the treatments plus the variation within the treatments.
D. between the treatments divided by the variation within the treatments.
10. A random sample of males and females involved in rear-end accidents results in the following Minitab summary:
N MEAN MEDIAN TRMEAN STDEV SEMEAN
FEMALES 33 23.91 20.00 23.38 9.77 1.70
MALES 38 28.87 28.50 28.44 9.67 1.57
What is the value of the test statistic (Z score)?
A. −4.96
B. 2.32
C. 1.64
D. −2.14
11. In testing a population variance or constructing a confidence interval for the population variance, an essential assumption is that
A. sample size exceeds 30.
B. expected frequencies equal or exceed 5.
C. the population is uniformly distributed.
D. the population is normally distributed.
12. In testing the difference between two population means using two independent samples, we use the pooled variance in estimating the standard error of the sampling distribution of the sample mean difference x̄1 − x̄2 if the
A. sizes are both greater than 30.
B. populations are at least normally distributed with equal variances.
C. populations are nonnormal with unequal variances.
D. ample sizes are both large.
13. A chi-square test for independence with 8 degrees of freedom results in a test statistic of 18.21. Using the chi-square table, the most accurate statement that can be made about the p-value for this test is that
A. p-value p-value > 0.025.
C. 0.025 > p-value > 0.01.
D. 0.10 > p-value > 0.05.
14. Given the significance level 0.05, the F-value for the degrees of freedom, df = (3,7) is
A. 6.16.
B. 4.35.
C. 8.89.
D. 4.12.
15. In testing for the equality of two population variances, when the populations are normally distributed, the 10% level of significance has been used. To determine the rejection region, it will be necessary to refer to the F table corresponding to an upper-tail area of
A. 0.20.
B. 0.90.
C. 0.05.
D. 0.10.
16. A “best-fit” mathematical equation for the values of two variables, x and y, is called
A. errors of prediction.
B. correlation analysis.
C. regression analysis.
D. scatter diagram.
17. Consider the following data values of variables x and y. Find the least squares regression line.
x 4 2 6 4 3
y 5 3 7 6 5
A. 21.206 + 1.073x
B. 1.122 + 1.073x
C. 1.659 + 0.932x
D. −1.045 + 0.932x
18. What is the slope of the line that passes through the points (−5, −8) and (3,8)?
A. −½
B. −2
C. 2
D. ½
19. In using the ANOVA models, the assumptions made about the data are
A. the samples are independent.
B. the population variances are equal.
C. the population distributions are normal.
D. all 3 assumptions made here about the data.