In a bivariate data $\Sigma x = 30\: \: \Sigma y = 400 \: \: \Sigma x^2=196 \: \: \Sigma xy = 850 \: \: n=10$ Find the regression coefficient of $y$ and $x$

Question

$\begin {array} {1 1} (A)\;3.2 & \quad (B)\;3.3 \\ (C)\;-3.3 & \quad (D)\;1.3 \end {array}$