A researcher models the relationship between hours of television watched per week (\(x\)) and test score (\(y\)) with the line of best fit \(y = -0.5x + 80\). According to the model, what test score is predicted for a student who watches 30 hours of television per week?

A line of best fit predicts that a student who practices piano for 10 hours will score 42 points on a performance exam. The student actually scores 45 points. What is the residual for this data point?

A study examining the relationship between outdoor temperature and hot chocolate sales finds a correlation coefficient of \(r = -0.92\). Which of the following best describes the relationship?

A survey of 200 people asked about coffee preference. The results are shown below. \[\begin{array}{|c|c|c|c|} \hline & \textbf{Hot Coffee} & \textbf{Iced Coffee} & \textbf{Total} \\ \hline \textbf{Under 30} & 30 & 70 & 100 \\ \textbf{30 and over} & 60 & 40 & 100 \\ \hline \textbf{Total} & 90 & 110 & 200 \\ \hline \end{array}\] Of those who prefer iced coffee, what fraction are under 30?