Exam 14: Correlation and Regression.

An analysis of regression is used to test the significance of a linear regression equation based on a sample of n = 20 individuals.What are the df values for the F-ratio?

A set of n = 15 pairs of scores (X and Y values)produces a correlation of r = 0.40.If each of the X values is multiplied by 2 and the correlation is computed for the new scores,what value will be obtained for the new correlation?

The line produced by the equation Y = 4X - 5 crosses the vertical axis at Y = 5.

For a regression equation with a slope of b = 3,if MX = 3 and MY = 10,then the Y-intercept for the equation is 1.

The value obtained for the sum of products,SP,determines the sign (+/-)for the Pearson correlation.

A researcher measures driving distance from college and weekly cost of gas for a group of commuting college students.What kind of correlation is likely to be obtained for these two variables?

If the value of the Pearson correlation is r = +1.00 or -1.00,then all data points in a scatter plot fit perfectly on a straight line.

What is the value of SP for the following set of data? 1 4 2 4 9 1

The phi-coefficient is the correct correlation to use when both X and Y are dichotomous variables.

Which of the following Pearson correlations shows the greatest strength or consistency of relationship?

If the Pearson correlation for a set of scores is equal to +1.00,then the Spearman correlation for the same scores would also be equal to +1.00.

A researcher obtains SSₓ = 20,SSʏ = 5,and SP = 7 for a set of n = 25 pairs of scores.The Pearson correlation for these scores is r = 7/10 = 0.70.

A linear regression equation is computed for a sample of n = 13 pairs of X and Y scores.For the analysis of regression testing the significance of the equation,what are the df values for the F-ratio?

For a two-tailed hypothesis test evaluating the significance of a correlation,the null hypothesis states that the sample correlation is zero.

For linear regression calculated for a sample of n = 20 pairs of X and Y values,what is the value for degrees of freedom for the predicted portion of the Y-score variance,MS regression?

If the following seven scores are ranked from smallest (#1)to largest,what rank should be assigned to a score of X = 6? Scores: 1,1,3,6,6,6,9

A set of n = 15 pairs of X and Y scores has SSₓ = 10,SSʏ = 40,and SP = 30.What is the slope for the regression equation for predicting Y from X?

A set of X and Y scores has a regression equation with a slope of b = 4.If the mean for the X values is MX = 2 and the mean for the Y values is MY = 6,what is the Y-intercept value for the regression equation?

A sample of n = 25 pairs of scores (X and Y values)produces a correlation of r = -0.40.Are these sample data sufficient to conclude that there is a significant non-zero correlation between X and Y in the population? Use a two-tailed test at the .05 level of significance.

The results from a research study indicate that adolescents who watch more violent content on television also tend to engage in more violent behavior than their peers.The correlation between amount of TV violence content and amount of violent behavior is an example of _______.