Questions 1 to 20: Select the best answer to each question. Note that a question

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Questions 1 to 20: Select the best answer to each question. Note that a question and its answers may be split across a page break, so be sure that you have seen the entire question and all the answers before choosing an answer. 1. The vertical distances between observed and predicted values of y are called A. methods of least squares. B. errors of prediction. C. scatterplots. D. least square lines. 2. 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 distributions are normal. D. the population variances are equal. 3. 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. D. determination equal to 1. 4. Another name for the residual term in a regression equation is A. residual analysis. B. homoscedasticity. C. random error. D. pooled variances. 5. 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. 6. A left-tail area in the chi-square distribution equals 0.95. For df = 10, the table value equals A. 20.483. B. 3.940. C. 15.987. D. 18.307. 7. 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. 2.14 D. 1.64 8. The F-statistic in a one-way ANOVA represents the variation A. between the treatments divided by the variation within the treatments. B. within the treatments divided by the variation between the treatments. C. between the treatments plus the variation within the treatments. D. within the treatments minus the variation between the treatments. 9. What is the slope of the line that passes through the points (5, 8) and (3,8)? A. 2 B. ½ C. 2 D. ½ 10. In testing a population variance or constructing a confidence interval for the population variance, an essential assumption is that A. the population is normally distributed. B. expected frequencies equal or exceed 5. C. the population is uniformly distributed. D. sample size exceeds 30. 11. 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. 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 x1 x2 if the A. populations are nonnormal with unequal variances. B. ample sizes are both large. C. sizes are both greater than 30. D. populations are at least normally distributed with equal variances. 13. Which of the following statements are true regarding the simple linear regression model yi = 0 + 1xi + i? A. 1 is the y-intercept of the regression line. B. yi is a value of the dependent variable (y) and xi is a value of the independent variable (x). C. i is a nonrandom error. D. 0 is the slope of the regression line. 14. 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, 38.076. B. 38.076, 38.99. C. 35.172, 38.99. D. 37.983, 35.172. 15. A "best-fit" mathematical equation for the values of two variables, x and y, is called A. regression analysis. B. correlation analysis. C. scatter diagram. D. errors of prediction. 16. 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, $5 B. $1, $5,000 C. $5, $5,000 D. $1, $80,005 17. Consider the following data values of variables x and y. x 4 2 6 4 3 End of exam Find the least squares regression line. y 5 3 7 6 5 A. 1.122 + 1.073x B. 1.045 + 0.932x C. 21.206 + 1.073x D. 1.659 + 0.932x 18. In testing the difference between two population means using two independent samples, the sampling distribution of the sample mean difference x1 x2 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. 19. 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. 0.05 > p-value > 0.025. B. 0.10 > p-value > 0.05. C. 0.025 > p-value > 0.01. D. p-value < 0.01. 20. A random sample of males and females involved in rear-end accidents results in the following Minitab summary: What is the standard error of the statistic between the two means? 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. 0.897 B. 1.635 C. 4.96 D. 2.31

Explanation / Answer

since more than 1 question is posted I will answer only one question

1)Error of prediction

2)option B. all are correct

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