What is an incorrect statement about linear regression analysis?

a. The regression line of best fit is achieved when the sum of squares for error is as small as possible.

b. The coefficient of determination indicates the ratio between the proportion of explained variation by the regression model and the proportion of error variation.

c. A more complex model, containing additional predictor variables, typically is helpful to increase the coefficient of determination.

d. None of them are incorrect.

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What is the correct statement about a prediction error in a linear regression analysis?

a. It indicates the variation in the response variable that is explained by the model.

b. It indicates the difference between the observed response and the value predicted by the model.

c. It measures the variance of the independent variable.

d. None of the above.

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in a multiple regression analysis, chooseone correct answerthat applies.

a. In multiple linear regression, the intercept represents the predicted value for the dependent variable when the values for all independent variables are equal to zero.

b. If one of the independent variables is a categorical variable, it is not allowed to perform a regression analysis but ANOVA.

c. Regression analysis can be used to make predictions of the predictor variable.

d. If, for example, theslopeof 2in a simple regression(b=2in the regression equation) means that the value of the Y variable increases by 1as the value of the X variable increases by 2.

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A researcher conducts a study where children are measured on the frequency of sharing at three different times over the course of the academic year.

Which ANOVA model is most appropriate for the analysis of this data?

a. Dependent sample t-test

b. Independent sample t-test

c. One-way between-subjects design

d. One-way repeated measures design

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When analyzing mean differences among more than two groups,doing independent t-tests on all possible pairs of means

a. Decreases the probability of a type 1 error

b. Does not change the probability of a type 1 error

c. Increases the probability of a type 1 error

d. Cannot be determined from the information provided

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The variance of X is 9,the variance of Y is 4,and the covariance between X and Y is 2.

What is the correlation coefficient,r?

a. 0.039

b. 0.056

c. 0.233

d. 0.333

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