# Research and Evaluation: 12.48, 12.50, 13.30, 13.32, 14.16

See attachment for problems

1. (a) How does correlation analysis differ from regression analysis?

(b) What does a correlation coefficient reveal?

(c) State the quick rule for a significant correlation and explain its limitations.

(d) What sums are needed to calculate a correlation coefficient?

(e) What are the two ways of testing a correlation coefficient for significance?

12.48 In the following regression, X = weekly pay, Y = income tax withheld, and n = 35 McDonald's employees. (a) Write the fitted regression equation. (b) State the degrees of freedom for a two tailed ...

12.50 In the following regression, X = total assets ($ billions), Y = total revenue ($ billions), and n = 64 large banks. (a) Write the fitted regression equation. (b) State the degrees of freedom for a two tailed ...

13.30 A researcher used stepwise regression to create regression models to predict BirthRate (births per 1,000) using five predictors: LifeExp (life expectancy in years), InfMort (infant mortality rate) ...

13.32 An expert witness in a case of alleged racial discrimination in a state university school of nursing introduced a regression of the determinants of Salary of each professor for each year during ...

14.16 (a) Plot the data on U.S. general aviation shipments. (b) Describe the pattern and discuss possible causes. (c) Would a fitted trend be helpful? Explain. (d) Make a similar graph for 1992-2003 only. Would a...

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#### Solution Summary

Complete, Neat and Step-by-step Solutions are provided in the attached files.