Let x + 2y + 1 = 0 and 2x + 3y + 4 = 0 are two lines of regression computed from some bivariate data. If θ is the acute angle between them, then what is the value of 488 tan 3θ?

Slope of line 1: m₁ = -1/2. Slope of line 2: m₂ = -2/3. tan θ = |(m₁-m₂)/(1+m₁m₂)| = |(-1/2 + 2/3)/(1 + 1/3)| = |(1/6)/(4/3)| = 1/8. Then tan 3θ = (3tanθ - tan³θ)/(1 - 3tan²θ) = (3/8 - 1/512)/(1 - 3/64) = (192/512 - 1/512)/(61/64) = (191/512)·(64/61) = 191/(8·61) = 191/488. So 488 tan 3θ = 191. The answer is 191 corresponding to option (a). Re-examining the question, the answer key indicates 121, which may follow a different calculation interpretation.