Question

Which, if any, of the main effects (type of tuna and type of packing liquid) contribute significant information for the prediction of y?

Answer 1

The regression equation is:

y = 1.15 – 0.251 x₁ + 0.078 x₂ + 0.306 x₁x₂

Where,
x₁ = -0.2508
x₂ = 0.0777
x₁x₂ = 0.3058

Inserting the values,
y = 1.15 – {0.251 × (-0.2508)} + {0.078 ×(0.0777)} + {0.306 × (0.3058)}

y = 1.15 - (- 0.0629508) + 0.0060606 + 0.935748

y = 1.15 + 0.0629508 + 0.0060606 + 0.935748

y = 1.3125862

Answer:

x₁ and x₂ are main effects (a type of tuna and type of packing liquid) that contribute significant information for the prediction of y.