You are evaluating the effect of different types of fertilizers on plant growth. You plant 12 tomato plants and divide them into three groups, where each group contains four plants. To the first group, you do not add fertilizer and the plants are watered with plain water. The second and third groups are watered with two different brands of fertilizer. After three weeks, you measure the growth of each plant in centimeters and calculate the average growth for each type of fertilizer. Identify the independent variable, dependent variable, control group, and experimental group from this experiment?

Control group - the plant group which has not received the fertilizers treatment.

Experimental group - the groups treated with different varieties of fertilizers.

Independent variable - amount of water and fertilizers

Dependent variable - growth of plants

Explanation:

A scientific experiment is performed in a way that the experimental samples are classified into the control and experimental groups. Also, the experiment involves various variables to be studied which can be classified as an independent variable and dependent variable.

In the given question, the experimental samples are:

1. Control group - The samples which are not provided with the variable being studied like the experiment is performed to test the effect of fertilizers and "the plant group which has not received the fertilizers treatment" can be considered the control group.

2. Experimental group - the samples in which the variable to be studied are provided with that is "the groups treated with different varieties of fertilizers."

In the given question, the variables are:

1. Independent variable - the variable which can be changed or modified or can change on their own like "amount of water and fertilizers" in the experiment.

2. Dependent variable - the variable which is being tested, can be measured and is dependent on an independent variable like the " growth of plants" in the experiment.