. 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. $1, $80,005 B. $1, $5,000 C. $1, $5 D. $5, $5,000 2. Which of the following statements are true regarding the simple linear regression model yi = β0 + β1xi + εi? A. yi is a value of the dependent variable (y) and xi is a value of the independent variable (x). B. εi is a nonrandom error. C. β0 is the slope of the regression line. D. β1 is the y-intercept of the regression line. 3. In testing the difference between two population means using two independent samples, the sampling distribution of the sample mean difference x̄1 − x̄2 is normal if the A. sizes are both greater than 30. B. populations are normal. C. populations are nonnormal and the sample sizes are large. D. population sizes are both greater than 30. 4. 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. 0.10. C. 0.90. D. 0.05. 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. 1.64 C. −4.96 D. −2.14 6. The vertical distances between observed and predicted values of y are called A. least square lines. B. methods of least squares. C. errors of prediction. D. scatterplots. 7. A “best-fit” mathematical equation for the values of two variables, x and y, is called A. correlation analysis. B. scatter diagram. C. regression analysis. D. errors of prediction. 8. A balanced experiment requires that A. at least one sample equal size is 30. B. an equal number of persons or test units receives each treatment. C. at least two treatment groups be used. D. the number of treatments equals the number of samples. 9. 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. 10. A left-tail area in the chi-square distribution equals 0.95. For df = 10, the table value equals A. 15.987. B. 3.940. C. 18.307. D. 20.483. 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. 13.120 and 40.647. B. 40.647. C. 12.401 and 39.364. D. 39.364. 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. ample sizes are both large. D. populations are nonnormal with unequal variances. 13. The object on which the response and factors are observed is called A. experimental unit. B. factor level. C. treatments. D. factors. 14. 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. 1.659 + 0.932x B. 21.206 + 1.073x C. −1.045 + 0.932x D. 1.122 + 1.073x 15. Another name for the residual term in a regression equation is A. pooled variances. B. residual analysis. C. homoscedasticity. D. random error. 16. An indication of no linear relationship between two variables would be a coefficient of A. correlation equal to −1. B. determination equal to −1. C. correlation of 0. End of exam D. determination equal to 1. 17. In using the ANOVA models, the assumptions made about the data are A. the samples are independent. B. the population variances are equal. C. all 3 assumptions made here about the data. D. the population distributions are normal. 18. 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. between the treatments divided by the variation within the treatments. D. within the treatments minus the variation between the treatments. 19. Lily Energy Systems manufacturer’s wood-burning heaters and fireplace inserts. One of its systems has an electric blower, which is thermostatically controlled. The blower is designed to automatically turn on when the temperature in the stove reaches 125°F and turn off at 85°F. Complaints from customers indicate that the thermostat control is not working properly. The company feels that the thermostat is acceptable if the variance in the cutoff temperature is less than or equal to 175. The company takes a sample of 24 thermostats and finds that the variance equals 289. The calculated chi-square test statistic and the table value for a 0.05 significance level are A. 37.983, 35.172. B. 35.172, 38.99. C. 38.076, 38.99. D. 37.983, 38.076. 20. Given the significance level 0.05, the F-value for the degrees of freedom, df = (3,7) is A. 4.35. B. 6.16. C. 8.89. D. 4.12.