Table 2.

Performance indicator for the cubic equation.

South Africa		Egypt		Nigeria
RMSE	MPE $\text{\%}$	RMSE	MPE $\text{\%}$	RMSE	MPE $\text{\%}$
6488.75	−3.005	2616.93	2.716	335.16	1.022
Senegal		Ethiopia		Kenya
RMSE	MPE $\text{\%}$	RMSE	MPE $\text{\%}$	RMSE	MPE $\text{\%}$
279.72	3.047	276.00	2.806	324.42	4.290