What happens when independent variables interact

Question

1. What is the alternate hypothesis in a problem where sales group two is predicted to be “. . . significantly less productive than sales group one?”

1.       HA: μ1 ≠ μ 2
2.       HA: μ 1= μ 2
3.       HA: μ 1> μ2
4.       HA: μ 1< μ 2

2. What is the advantage of a one-tailed test over a two-tailed test?

1.       Less data variability in the groups involved.
2.       Smaller critical values indicate significance.
3.       Rejecting at HO = .05 involves less chance of error.
4.       There are fewer calculations to make.

3. A “factorial ANOVA” used to analyze a business problem refers to which?

1.      A problem that has multiple independent variables.
2.       A problem that uses several different kinds of measurement.
3.       A problem in which the factor of interest hasn’t been determined.
4.       A problem for which the variables are unknown.

4. Theoretically, how many independent variables can a factorial ANOVA accommodate?

1.       1
2.       2
3.       4
4.       any number

5. What happens when independent variables interact?

1.       Their independent effects become the point of focus.
2.       They have a combined effect.
3.       Their effects become unpredictable.
4.       Their effects cannot be analyzed by an ANOVA model.

6. To what does “main effect” refer in an ANOVA of company sales?

1.       It means the “primary influence”.
2.       It refers to the sum of the error variance.
3.       It designates the interaction of variables.
4.       It refers to an independent variable.

7. Which reflects an advantage that ANOVA has over t-test?

1.       ANOVA is a more powerful test than t-test.
2.       ANOVA doesn’t require an interval-scale dependent variable.
3.       ANOVA controls type I error for any number of comparisons.
4.       ANOVA accommodates larger groups than t-test.

8. If ANOVA reveals that four different departments have significantly different levels of productivity, what will a post-hoc test indicate?

1.       Whether teach of those comparisons were important.
2.       Which groups were significantly different from which.
3.       The effect size.
4.       The size of the confidence interval.

9. If one of the independent variables in a factorial ANOVA is the customer’s gender, and the factor is statistically significant, why is a post-hoc test unnecessary?

1.       There are only two levels of gender.
2.       There may not be any other significant independent variable.
3.       Gender differences in purchasing habits are rarely important.
4.       There isn’t any way to have an interaction with a gender variable.

10. How is the mean square derived from the sum of squares?

1.       The sum of squares is divided by their degrees of freedom.
2.       The mean square is the reciprocal of the sum of squares.
3.       It is the sum of squares divided by the square root of the number.
4.       It is the sum of squares times its degrees of freedom.