In problem 14.1, data regarding voter turnout in five cities was presented. For the sake of convenience, the data for three of the variables are presented again here along with descriptive statistics and zero-order correlations.

PS unemployment direct? (HINT: Use Formula 16.1 and see Section 16.2.)

b. Compute the partial correlation coefficient for the relationship between turnout (Y) and negative advertising (X) while controlling for the effect of unemployment (Z). What effect does this have on the bivariate relationship? Is the relationship between turnout and negative advertising direct?

(HINT: Use Formula 16.1 and see Section 16.2.

You will need this partial correlation to compute the multiple correlation coefficient.)

c. Find the unstandardized multiple regression equation with unemployment (X1) and negative ads (X2) as the independent variables. What turnout would be expected in a city in which the unemployment rate was 10% and 75% of the campaign ads were negative? (HINT: Use Formulas 16.4 and 16.5 to compute the partial slopes and then use Formula 16.6 to find

a, the Y intercept. The regression line is stated in Formula 16.3. Substitute 10 for X1 and 75 for X2 to compute predicted Y.)

d. Compute beta-weights for each independent variable. Which has the stronger impact on turnout?

(HINT: Use Formulas 16.7 and 16.8 to calculate the beta-weights.)

e. Compute the multiple correlation coefficient (R)

and the coefficient of multiple determination

(R2). How much of the variance in voter turnout is explained by the two independent variables?

Unemployment Negative Rate Ads Turnout 0.95

0.87 Unemployment Rate 0.70 City Turnout Unemployment % Negative Rate Ads A 55 5 60 B 60 8 63 C 65 9 55 D 68 9 53 E 70 10 48 Mean 636 82 558 s 55 17 53

a. Compute the partial correlation coefficient for the relationship between turnout (Y) and unemployment (X) while controlling for the effect of negative advertising (Z). What effect does this control variable have on the bivariate relationship? Is the relationship between turnout and

(HINT: Use Formula 16.11. You calculated in part b of this problem.)

f. Write a paragraph summarizing your conclusions about the relationships among these three variables.