Answer:
No
Step-by-step explanation:
Based on the exact methodology that Raul is using he will never produce valid results. This is mainly due to the fact that there are too many changing variables in his experiment. In order to produce valid results, the experiment can only have one changing variable (independent variable) at a time, while all of the other variables need to be controlled/constant. This would allow Raul to isolate which change is actually causing the desired effect in the plants. The way that Raul has his experiment set-up he will not be able to pinpoint exactly what variable or aspect is actually causing the growth of the plants.