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107.Here is an Excel ANOVA table for an experiment that analyzed two factors that may affect patients' blood pressure (some information is missing).At α = .05 the effect of medication type is: A.significant. B.insignificant. C.borderline. 108.Here is an Excel ANOVA table for an experiment that analyzed two factors that may affect patients' blood pressure.
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21.Tukey's test for five groups would require 10 comparisons of means. 22.ANOVA is robust to violations of the equal-variance assumption as long as group sizes are equal. 23.Levene's test for homogeneity of variance is attractive because it does not depend on the assumption of normality. 24.Tukey's test with seven groups.
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11.Tukey's test is similar to a two-sample t-test except that it pools the variances for all c samples. 12.Tukey's test is not needed if we have the overall F statistic for the ANOVA. 13.Interaction plots that show crossing lines indicate likely interactions. 14.Interaction plots that show parallel lines would suggest.
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31.In simple linear regression, the coefficient of determination (R2) is estimated from sums of squares in the ANOVA table. 32.In simple linear regression, the p-value of the slope will always equal the p-value of the F statistic. 33.An observation with high leverage will have a large residual (usually an outlier). 34.A prediction interval.
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True / False Questions 1.In regression the dependent variable is referred to as the response variable. 2.If a regression model's F test statistic is Fcalc = 43.82, we could say that the explained variance is approximately 44 percent. 3.In a regression, the model with the best fit is preferred over all.
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37.Which is not assumed in ANOVA? A.Observations are independent. B.Populations are normally distributed. C.Variances of all treatment groups are the same. D.Population variances are known. 38.In a one-factor ANOVA, the computed value of F will be negative: A.when there is no difference in the treatment means. B.when there is no difference within the treatments. C.when the SST (total).
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Short Answer Questions134.Pedro became interested in vehicle fuel efficiency, so he performed a simple regression using 93 cars to estimate the model CityMPG = β0 + β1 Weight, where Weight is the weight of the vehicle in pounds. His results are shown below. Write a brief analysis of these results,.
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127.A multinational firm manufactures several types of 1280 × 1024 LCD displays in several locations. They designed a sampling experiment to analyze the number of pixels per screen that have significant color degradation after 52,560 hours (six years of continuous use) using accelerated life testing. The Excel ANOVA table for.
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86.A corporate analyst is testing whether mean inventory turnover has increased. Inventory turnover in six randomly chosen product distribution centers (PDCs) is shown.The degrees of freedom for the appropriate test would be: A.6. B.5. C.4. D.12. 87.A corporate analyst is testing whether mean inventory turnover has increased. Inventory turnover in six randomly chosen product distribution.
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112.Which estimated multiple regression contains an interaction term? A. B.. C. 113.Which estimated multiple regression allows a test for nonlinearity? A.. B. C.. 114.Which estimated multiple regression has nonlinearity tests? A. B.. C. 115.Simple tests for nonlinearity in a regression model can be performed by A.squaring the standard error. B.including squared predictors. C.deleting predictors one at a time. 116.The regression equation Salary = 35,000 + 3500.
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102.Which Excel function will give the p-value for overall significance if a regression has 75 observations and 5 predictors and gives an F test statistic Fcalc = 3.67? A.=F.INV(.05, 5, 75) B.=F.DIST(3.67, 4, 74) C.=F.DIST.RT(3.67, 5, 69) D.=F.DIST(.05, 4, 70) 103.The ScamMore Energy Company is attempting to predict natural gas consumption for the month of.
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111.A local trucking company fitted a regression to relate the cost of its shipments as a function of the distance traveled. The Excel fitted regression is shown.Based on this estimated relationship, when distance increases by 50 miles, the expected shipping cost would increase by: A.$286. B.$143. C.$104. D.$301. 112.If SSR is 2592 and SSE is.
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Short Answer Questions 148.The table below shows raw data on air pollutant levels (micrograms of particulate per liter of air) sampled at four different randomly chosen times of day on three different freeways. State the most reasonable hypotheses. What test would a statistician probably use? How many total degrees of freedom?.
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41.Non-normal residuals lead to biased estimates of the coefficients in a regression model. 42.A large VIF (e.g., 10 or more) would indicate multicollinearity. 43.Heteroscedasticity exists when all the errors (residuals) have the same variance. 44.Multicollinearity refers to relationships among the independent variables. 45.A squared predictor is used to test for.
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121.Which is not an assumed property of the errors in a population regression model? A.They are unobservable. B.They are independent. C.They have zero variance. D.They are normally distributed. 122.If the residuals from a fitted regression violate the assumption of homoscedasticity, we know that: A.they are normally distributed. B.they are independent of one another. C.their variance is not constant. D.there.
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Short Answer Questions 127.Using state data (n = 50) for the year 2000, a statistics student calculated a matrix of correlation coefficients for selected variables describing state averages on the two main scholastic aptitude tests (ACT and SAT). (a) In the spaces provided, write the two-tailed critical values of the correlation.
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66.Nacirema Airlines is buying a fleet of new fuel-efficient planes. The HogJet and the LitheJet both meet their price and performance needs, and both planes meet EPA noise guidelines. However, the quieter plane is preferred. Each plane is flown through a typical takeoff and landing sequence 10 times, while remote.
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137.Refer to the following partial ANOVA results from Excel (some information is missing).The overall sample size was: A.24. B.23. C.22. D.18. 138.Refer to the following partial ANOVA results from Excel (some information is missing).How many pressure levels were observed? A.4 B.3 C.2 D.1 139.Refer to the following partial ANOVA results from Excel (some information is missing).At α = .05, the.
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81.Which is indicative of an inverse relationship between X and Y? A.A negative F statistic B.A negative p-value for the correlation coefficient C.A negative correlation coefficient D.Either a negative F statistic or a negative p-value 82.Which is not correct regarding the estimated slope of the OLS regression line? A.It is divided by its standard error to.
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62.Which is not a name often given to an independent variable that takes on just two values (0 or 1) according to whether or not a given characteristic is absent or present? A.Absent variable B.Binary variable C.Dummy variable 63.Using a sample of 63 observations, a dependent variable Y is regressed against two variables X1.
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Multiple Choice Questions 27.Which is the Excel function to find the critical value of F for α = .05, df1 = 3, df2 = 25? A.=F.DIST(.05, 2, 24) B.=F.INV.RT(.05, 3, 25) C.=F.DIST(.05, 3, 25) D.=F.INV(.05, 2, 24) 28.Which Excel function gives the right-tail p-value for an ANOVA test with a test statistic Fcalc = 4.52, n.
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117.A firm is concerned with variability in hourly output at several factories and shifts. Here are the results of an ANOVA using output per hour as the dependent variable (some information is missing).The original data matrix has how many treatments (rows × columns)? A.4 B.6 C.3 D.8 118.A firm is concerned with variability in hourly.
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Short Answer Questions113.Random samples of students were compared to see whether or not there was a difference in the proportion favoring the university's proposed switch from MWF (three-day) classes to MW and TR (two-day) classes. The results shown below are from MegaStat. Analyze these results thoroughly. 114.The table below compares two.
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67.Sound levels are measured at random moments under typical driving conditions for various full-size truck models. The ANOVA results are shown below.The test statistic for Hartley's test for homogeneity of variance is: A.2.25. B.5.04. C.4.61. D.4.45. 68.Refer to the following partial ANOVA results from Excel (some information is missing).ANOVA TableThe number of treatment groups is: A.5. B.4. C.3. D.impossible.
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41.A simple decimal transformation (e.g., from 18,291 to 18.291) often improves data conditioning. 42.Two-tailed t-tests are often used because any predictor that differs significantly from zero in a two-tailed test will also be significantly greater than zero or less than zero in a one-tailed test at the same α.43.A predictor that.
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106.Jason wants to perform a two-tailed test for equality between two independent sample proportions. Each sample has at least 10 "successes" and 10 "failures." Jason's test statistic is -1.44. What is his p-value? A..1498 B..0749 C..9251 D.Between .01 and .05 107.Does the Speedo Fastskin II Male Hi-Neck Bodyskin competition racing swimsuit improve a swimmer's 200-yard.
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47.Identify the degrees of freedom for the treatment and error in this one-factor ANOVA (blanks indicate missing information). A.4, 24 B.3, 20 C.5, 23 48.For this one-factor ANOVA (some information is missing), how many treatment groups were there? A.Cannot be determined B.3 C.4 D.2 49.For this one-factor ANOVA (some information is missing), what is the F-test statistic? A.0.159 B.2.833 C.1.703 D.Cannot be determined 50.Refer.
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57.Refer to the following partial ANOVA results from Excel (some information is missing).The critical value of F at α = 0.05 is: A.1.645. B.2.84. C.3.10. D.4.28. 58.Refer to the following partial ANOVA results from Excel (some information is missing).At α = 0.05, the difference between group means is: A.highly significant. B.barely significant. C.not quite significant. D.clearly insignificant. 59.The Internal Revenue.
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31.A multiple regression with 60 observations should not have 13 predictors. 32.A regression of Y using four independent variables X1, X2, X3, X4 could also have up to four nonlinear terms (X2) and six simple interaction terms (XjXk) if you have enough observations to justify them. 33.When autocorrelation is present,.
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82.Based on these regression results, in your judgment which statement is most nearly correct (Y = highway miles per gallon in 91 cars)? A.The number of predictors is rather small. B.Some predictors are not contributing much. C.Prediction intervals would be fairly narrow in terms of MPG. D.The overall model lacks significance and/or predictive power. 83.In.
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Multiple Choice Questions52.In a multiple regression with six predictors in a sample of 67 U.S. cities, what would be the critical value for an F-test of overall significance at α = .05? A.2.29 B.2.25 C.2.37 D.2.18 53.In a multiple regression with five predictors in a sample of 56 U.S. cities, what would be the critical.
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96.The folded F-test for equality of variances: A.is rarely used because of its complexity. B.requires looking up the critical value for α/2. C.puts the smaller variance in the numerator. D.requires looking up two critical values of F instead of one. 97.An F-test for equality of variances gives a p-value of .003. At α = .05,.
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77.Refer to the following partial ANOVA results from Excel (some information is missing).ANOVA tableOur decision about the hypothesis of equal treatment means is that the null hypothesis: A.cannot be rejected at α = .05. B.can be rejected at α = .05. C.can be rejected for any typical value of α. D.cannot be assessed from.
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92.Which statement is incorrect? A.Positive autocorrelation results in too many centerline crossings in the residual plot over time. B.The R2 statistic can only increase (or stay the same) when you add more predictors to a regression. C.If the F-statistic is insignificant, the t statistics for the predictors also are insignificant at the same.
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True / False Questions 1.ANOVA is a procedure intended to compare the variances of several groups (treatments). 2.ANOVA is a procedure intended to compare the means of several groups (treatments). 3.If you have four factors (call them A, B, C, and D) in an ANOVA experiment with replication, you could have.
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91.In a simple bivariate regression with 25 observations, which statement is most nearly correct? A.A nonstandardized residual whose value is ei = 4.22 would be considered an outlier. B.A leverage statistic of 0.16 or more would indicate high leverage. C.Standardizing the residuals will eliminate any heteroscedasticity. D.Non-normal residuals imply biased coefficient estimates, a major.
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Multiple Choice Questions61.The variable used to predict another variable is called the: A.response variable. B.regression variable. C.independent variable. D.dependent variable. 62.The standard error of the regression: A.is based on squared deviations from the regression line. B.may assume negative values if b1 < 0. C.is in squared units of the dependent variable. D.may be cut in half to get an.
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True / False Questions 1.A scatter plot is used to visualize the association (or lack of association) between two quantitative variables.2.The correlation coefficient r measures the strength of the linear relationship between two variables. 3.Pearson's correlation coefficient (r) requires that both variables be interval or ratio data.Correlation assumes quantitative data with at.
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