Question

question 4 (1 point) saved listen researchers who wanted to study plant growth, grew plants in two different types of rooms. in one room, researchers set up taped conversations that played 24 hours a day. the other room was silent. the researchers found that the plants grew better in the room that had the conversations playing. in this study, the two different types of rooms that were set up (conversation or silence) would be a placebo effect. the independent variable. an extraneous variable. the dependent variable.

Explanation:

In experimental design, the independent variable is the factor that is intentionally manipulated by researchers to test its effect on another variable. Here, the researchers manipulated the room condition (conversation vs. silence) to observe changes in plant growth, so this condition is the independent variable. A placebo effect refers to a response from a non-active treatment, extraneous variables are uncontrolled factors that may affect results, and the dependent variable is the outcome being measured (plant growth in this case).

Answer:

B. the independent variable.