Question

a farmer divided his land into 2 sections. there is no difference in the quality of the soil between the 2 sections of land. he used type a seeds in the first section and type b seeds in the second section. after 3 months, the heights of the crops are measured across the two sections of land. is the study observational or experimental? if it is an experiment, what is the controlled factor?

select the correct answer below:

○ the study is an observational study.

○ the study is an experiment. the controlled factor is the seed type.

○ the study is an experiment. the controlled factor is the land.

○ the study is an experiment. the controlled factor is the growth of the crops.

Explanation:

An experimental study involves actively manipulating a variable to observe its effect, while an observational study only observes without intervention. Here, the farmer intentionally assigned different seed types to two identical land sections, so it is an experiment. The controlled factor is the variable that is held constant to isolate the effect of the manipulated variable; the land quality is identical, so the land is the controlled factor, and seed type is the manipulated independent variable.

Answer:

The study is an experiment. The controlled factor is the land.