Linear Regression & Least Squares Method: Videos & Practice Problems

A team of psychologists wants to know if there is a positive linear relationship between the perceived confidence and perceived leadership ability of individuals based on their profile pictures. They collect ratings from $120$ raters for $60$ subjects, converting each rater’s scores to $z$-scores to control for individual bias. The mean $z$-score for perceived confidence and leadership ability is calculated for each subject. The correlation coefficient between the perceived confidence and leadership ability $z$-scores is found to be $r=0.35$. The normal probability plot of residuals shows normality. Test whether a positive linear relationship exists between perceived confidence and perceived leadership ability.