Multiple Choice Questions in Statistics

1. For the hypothesis test, , with n1 = 10 and n2 = 10, the F-test statistic is 2.56. At the 0.01 level of significance, we would reject the null hypothesis.
TRUE
FALSE

2. If the endpoints of a confidence interval for the difference between a pair of treatment means are both positive numbers, then the treatment means are not different.
TRUE
FALSE

3. Which statement is correct about the F distribution?
a. Cannot be negative
b. Cannot be positive
c. Is the same as the t distribution
d. Is the same as the z distribution

4. Analysis of variance is used to
a. compare nominal data.
b. compute t test.
c. compare population proportion.
d. simultaneously compare several population means.

5. A large department store examined a sample of the 18 credit card sales and recorded the amounts charged for each of three types of credit cards: MasterCard, Visa and Discover. Six MasterCard sales, seven Visa and five Discover sales were recorded. The store used ANOVA to test if the mean sales for each credit card were equal. What are the degrees of freedom for the F statistic?
a. 18 in the numerator, 3 in the denominator
b. 3 in the numerator, 18 in the denominator
c. 2 in the numerator, 15 in the denominator
d. 6 in the numerator, 15 in the denominator

7. If an ANOVA test is conducted and the null hypothesis is rejected, what does this indicate?
a. Too many degrees of freedom
b. No difference between the population means
c. A difference between at least one pair of population means
d. None of these

11. How is the degree of association between a set of independent variables and a dependent variable measured?
a. Confidence intervals.
b. Autocorrelation
c. Coefficient of multiple determination
d. Standard error of estimate

12. If the coefficient of multiple determination is 0.81, what percent of variation is not explained?
a. 19%
b. 90%
c. 66%
d. 81%

13. If the correlation between the two independent variables of a regression analysis is 0.11 and each independent variable is highly correlated to the dependent variable, what does this indicate? (Points: 1)
a. Only one of the independent variables should be used in the regression equation.
b. The independent variables are strongly related.
c. Two separate regression equations are required.
d. Both independent variables should be used to predict the dependent variable.

14. What can we conclude if the global test of regression does not reject the null hypothesis?
a. A strong relationship exists among the variables
b. No relationship exists between the dependent variable and any of the independent variables
c. The independent variables are good predictors
d. Good forecasts are possible

15. What are the degrees of freedom associated with the regression sum of squares?
a. Number of independent variables
b. 1
c. F-ratio
d. (n 2)

16. Which of the following is a characteristic of the F-distribution?
a. Normally distributed
b. Positively skewed
c. Negatively skewed
d. Equal to the t-distribution

17. Multiple regression analysis is applied when analyzing the relationship between
a. An independent variable and several dependent variables
b. A dependent variable and several independent variables
c. Several dependent variables and several independent variables
d. Several regression equations and a single sample