1. The vertical distances between observed and predicted values of y are called
A. errors of prediction.
B. least square lines.
C. scatterplots.
D. methods of least squares.
2. 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. 4.96
C. 1.635
D. 0.897
3. Consider the following data values of variables x and y.
Find the least squares regression line.
A. -1.045 + 0.932x
B. 1.659 + 0.932x
C. 21.206 + 1.073x
D. 1.122 + 1.073x
4. 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 result in an increase of _______ in sales.
A. $5, $5,000
B. $1, $5
C. $1, $5,000
D. $1, $80,005
5. A random sample of males and females involved in rear-end accidents results in the following Minitab summary:
What is the value of the test statistic (Z score)?
|
|
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
|
A. 2.32
B. -4.96
C. 1.64
D. -2.14
6. A left-tail area in the chi-square distribution equals 0.95. For df= 10, the table value equals
A. 3.940.
B. 15.987.
C. 18.307.
D. 20.483.
7. Another name for the residual term in a regression equation is
A. random error.
B. pooled variances.
C. residual analysis.
D. homoscedasticity.
8. 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 x¯1 - x¯2 if the
A. populations are nonnormal with unequal variances.
B. populations are at least normally distributed with equal variances.
C. sizes are both greater than 30.
D. ample sizes are both large.
9. With larger and larger numbers of categories in chi-square tests, the chi-square distribution takes on the shape of the _______ distribution.
A. binomial
B. normal
C. t-
D. Poisson
10. An indication of no linear relationship between two variables would be a coefficient of
A. determination equal to -1.
B. correlation of 0.
C. correlation equal to -1.
D. determination equal to 1.
11. 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. 40.647.
B. 13.120 and 40.647.
C. 39.364.
D. 12.401 and 39.364.
12. What is the slope of the line that passes through the points (-5, -8) and (3,8)?
A. 2
B. -2
C. ½
D. -½
13. Given the significance level 0.025, the F-value for the degrees of freedom, df= (7,3) is
A. 8.45.
B. 5.89.
C. 27.67.
D. 14.62.
14. The F-statistic in a one-way ANOVA represents the variation
A. within the treatments divided by the variation between the treatments.
B. between the treatments plus the variation within the treatments.
C. within the treatments minus the variation between the treatments.
D. between the treatments divided by the variation within the treatments.
15. A balanced experiment requires that
A. at least two treatment groups be used.
B. the number of treatments equals the number of samples.
C. an equal number of persons or test units receives each treatment.
D. at least one sample equal size is 30.
16. The object on which the response and factors are observed is called
A. factors.
B. treatments.
C. experimental unit.
End of exam
D. factor level.
17. In testing the difference between two population means using two independent samples, the sampling distribution of the sample mean difference x¯1 - x¯2 is normal if the
A. sizes are both greater than 30.
B. population sizes are both greater than 30.
C. populations are normal.
D. populations are nonnormal and the sample sizes are large.
18. In using the ANOVA models, the assumptions made about the data are
A. the samples are independent.
B. all 3 assumptions made here about the data.
C. the population variances are equal.
D. the population distributions are normal.
19. 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. 0.05.
B. 0.20.
C. 0.10.
D. 0.90.
20. 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 < 0.01.
B. 0.10 >p-value > 0.05.
C. 0.05 >p-value > 0.025.
D. 0.025 >p-value > 0.01.