Correlation, Part I. What would be the correlation between the ages of husbands and wives if men always married woman who were
(a) 3 years younger than themselves?
(b) 2 years older than themselves?
(c) half as old as themselves?
Correlation, Part II. What would be the correlation between the annual salaries of males and females at a company if for a certain type of position men always made
(a) $5,000 more than women?
(b) 25% more than women?
(c) 15% less than women?
Units of regression. Consider a regression predicting weight (kg) from height (cm) for a sample of adult males. What are the units of the correlation coefficient, the intercept, and the slope?
Which is higher? Determine if I or II is higher or if they are equal. Explain your reasoning. For a regression line, the uncertainty associated with the slope estimate, b1, is higher when
I. there is a lot of scatter around the regression line or
II. there is very little scatter around the regression line