The student clearly states the independent and dependent variables in the research question, identifying the increasing masses of black tea powder and NPK fertilizer as independent variables, while the dependent variable is the sugar concentration in Long beans measured by Brix percentage. The research question also describes the method of analysis, specifying the use of a refractometer for measuring sugar concentration. Furthermore, the student provides relevant background theory on fertilizers and their impact on plant growth, establishing a strong foundation for the investigation. However, there is a lack of explanation regarding the choice of techniques for measuring the variables, as well as insufficient discussion on the number of trials and controlled variables, which could enhance the justification and reliability of the methodology. Despite these shortcomings, the student effectively addresses safety, ethical, and environmental issues associated with the investigation.
