In the Materials and Methods, sub-section headed Statistical analysis, the two equations given are not correct. They should read:
$$Y = b_0 + b_1 X_1 + b_2 X_2 +... + b_n X_n + e{}_{ij}$$
and
$$Y_i = b_0 + b_1 X_i + b_2 X_i^2 + b_3 X_i^3 + e_i $$
Published online by Cambridge University Press: 11 February 2013
In the Materials and Methods, sub-section headed Statistical analysis, the two equations given are not correct. They should read:
and