Pesticide A is more effective than B. After both were applied in a garden, there were fewer in the area sprayed with pesticide A after two weeks. Independent And Dependent Variable-

Independent variable: Type of pesticide

Dependent variable: Number of pests killed

Explanation:

A variable is a factor that can take on different values. In scientific researches, there are three main kinds of variables; Independent, dependent and control variables.

Independent variable: an independent variable is directly under the control of the experimenter. It is the variable that gives a value to the dependent value based on its manipulations. In this example, the type of pesticide used is dependent on the experimenter, either A or B

Dependent variable: This is a variable that is being studied. It is not directly under the manipulation of the experimenter but has its values from the changes of the independent variables. In this example, the number of pests killed is dependent on the changing of the type of pesticide used.

Control Variable: Control variables are extraneous variables that are not being directly studied but can affect the outcome of interest hence needs to be held constant.

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.

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