Compute the least-squares regression line for predicting y from x given the following summary statistics:

Question

x̄ = 8.1

 s_x = 1.2

 ȳ = 30

4s_y = 1.9 

r = −0.85

Answer 1

y=mx + b is the general form of the regression line equation where

m = r(sy/sx) and b = the mean y - m(mean x)

just plug in the numbers

there's an ambiguity in your problem though. If mean y = 304 and sy=1.9 then

y=-1.346x + 314.901 is close to the exact answer

but you have y=30 and 4sy=1.9, which would give a different line. It looks like a typo that way though.