7. The following table gives information on the incomes (in thousands of dollars) and charitable contributions (in hundreds of dollars) for the past year for a sample of ten households. \begin{tabular}(|1|CCCCCCCCCC \hline Income $C\mathrm{x})$ & 56 & 36 & 102 & 72 & 52 & 91 & 50 & 62 & 80 & 40 W \hline Charitable donations $\mathrm{y})$ & 10 & 4 & 29 & 23 & 3 & 28 & 8 & 16 & 18 & 2 Vhline \end{tabular) a) Calculate the linear correlation coefficient, $r$. b) Find the equation for the least-squares regression line (line-of-best-fit). c) Predict the charitable donation of a household with an income of $1$ 78,000$. 15 Points SP.SD. 105