The amounts of 6 restaurant bills and the corresponding amounts of the tips are given in the table below. $$\begin{array}{c|cccccc} \mbox{Bill} & 49.72 & 106.27 & 88.01 & 70.29 & 43.58 & 64.30 \cr \hline \mbox{Tip} & 5.28 & 16.00 & 10.00 & 10.00 & 5.50 & 7.70 \cr \end{array}$$ Find the following:

The regression equation is $\hat{y}=$ $+$ $x.$
If the amount of the bill is $$50,$ the best prediction for the amount of the tip is