The dependent variable is the one that is the output of a function, its value is tied to the value of another variable. The independent variable is the input of a function, its value will determine the value of the dependent one. In this case, the independent variable is the "Type of Fertilizer" and the dependent one is the "Yield of tomato". This is because the type of fertilizer will influence the yield of tomatoes, a better fertilizer will yield more tomatoes.
