QM 213 final
. If the correlation coefficient is a positive value, then the slope of the regression line: a. must also be positive b. can be either negative or positive c. can be zero d. must be negative e. none of the above
A
12. Which of the following best describes the least squares criterion? a. it identifies the best fitting line as the line that minimizes the sum of the squared vertical distances of points from the line b. the best fitting line minimizes the sum of the horizontal distances from the line c. it minimizes the sum of the absolute distances from the line d. it is a measure of the goodness of fit of the estimated regression equation e. none of the above
A
19. In experimental design, factors not of primary interest in a study that may serve to obscure experimental results due to their effect on the response variable are called a. extraneous factors b. rigid factors c. experimental factors d. guided factors
A
16. In multiple linear regression, which of the following is NOT true about the hypothesis tests: a. the F test measures the overall significance of the regression equation b. the t test measures the significance of an individual regression coefficient c. F = t2 just as in simple linear regression d. the null hypothesis for the F test is that all the slopes are equal to 0 e. the null hypothesis for the t test is that the particular slope is equal to 0
C
8. The normal distribution can be used to approximate the t distribution when a. standard deviations are small b. sample size is large c. the t distribution is skewed d. a normal table is unavailable e. none of the above
B
20. An experiment in which we can assess the simultaneous effect of multiple factors on a response variable and in which all factor combinations are represented is called a a. partitioning experiment b. cross reference experiment c. block experiment d. factorial experiment
D
1. Which of the following is a condition for a binomial probability experiment? a. the experiment involves a number of "trials," represented by n. b. only two outcomes are possible on each of the trials. c. the trials are statistically independent. d. the probability of success, p, on any one trial remains constant throughout the experiment. e. all of the above
E
15. Which of the following is true regarding the F distribution? a. it is the ratio of two variances from two normal populations b. it is not symmetric c. values can never be negative d. it has numerator degrees of freedom from sample 1 and denominator degrees of freedom from sample 2 e. all of the above
E
2. Which of the following is a condition for a Poisson probability experiment? a. we need to be assessing the probability for the number of occurrences of some event per unit time, space, or distance. b. the average number of occurrences per unit of time, space, or distance is constant. c. the average number of occurrences per unit of time, space, or distance is proportionate to the size of the unit of time, space, or distance involved. d. individual occurrences of the event are random and statistically independent. e. all of the above
E
7. Which of the following is NOT a common step in hypothesis testing? a. state the null and alternative hypotheses b. use the significance level to establish the reject H0 region of the test c. compute the p-value for the sample result d. apply the decision rule and make your decision e. none of the above; all are steps
E
Which of the following is true regarding the F distribution? a. it is the ratio of two sample variances b. it is not symmetric c. values can never be negative d. it has numerator degrees of freedom from sample 1 and denominator degrees of freedom from sample 2 e. all of the above
E
6. In hypothesis testing, we reject the null hypothesis if the p-value > .
False
10. The coefficient of determination r2, a measure of the goodness of fit of the estimated regression equation, is the ratio of the explained variation in y to the total variation in y, and takes on values between 0 and 1.
True
13. In simple linear regression analysis, when testing for significance, the F test and the t test will always result in the same conclusion.
True
14. The mean square (MS) values in an Analysis of Variance (ANOVA) for multiple regression are the sum of squares (SS) values divided by their corresponding degrees of freedom.
True
17. The F distribution can be used to describe how the ratio of two sample variances behaves when the two samples have been independently selected from normal populations with the same variance.
True
3. As the sample size increases, the margin of error in an interval estimate of a population proportion decreases.
True
4. For the sampling distribution of the sample proportion, the distribution is approximately normal as long as n > 30.
True
5. In hypothesis testing, the critical value is a number that establishes the boundary of the reject H0 region of the test.
True
9. A procedure used for finding the equation of a straight line that provides the best fit by minimizing the sum of the squared vertical distances of points from the line is called the least squares method.
True