What is the interpretation of the slope β1\beta_1β1 in the equation y^=β0+β1x\hat{y} = \beta_0 + \beta_1 xy^=β0+β1x?
The predicted value of yyy when x=0x=0x=0.
The average change in yyy for a one-unit change in xxx.
The variance of the error term.
The proportion of explained variance.