Linear Regression and finding Correlation Coefficient

Question

In a Simple Linear Regression $y= \alpha + \beta x + \epsilon $, we gather this information:

$S_y=20, S_x=5, \widehat{\beta} = 0.2 $

how I could find Instance Correlation Coefficient between x and y?

I ran into this problem for gathering some information in my Research.

Answer 1

The relation $$ \hat \beta = \frac{rS_y}{S_x} $$ implies that $0.2 = 4r$ and therefore $r = 0.05$.