Four pairs of data yield r = 0.942 and the regression equation (predicated value of y =3x. Also, the mean of y=12.75. What is the best predicted value of y for x=2.6?

Can you help? I'm not sure what formula to use. I'm trying to figure out if I'm suppose to use the regression equation. However, I don't know how to find the slope and y-intercept.

Thanks,