Answer:
The correct option is;
4. The initial amount of plant food
Step-by-step explanation:
The x-intercept is the point and the value of the variable, x at which the function measured f(x) is 0
From the information given, the quantities measured are the quantity of plant food added and height of the bean sprout
Given the nature of the observational experiment, we have that, the variable x which can determined by the researcher is the quantity of the added plant food while the function of the variable y = f(x) is the height of the bean sprout.
Therefore, y = 0 which is the x-intercept, represents the start of the experiment (consisting of natural numbers) which gives the initial amount of plant food added to the soil.
