You have designed an experiment manipulating room temperature (cold, warm, or hot), noise level (quiet or loud), and room color (pink, blue, or black). How many main effects are possible?

3 main effects are possible.

Step-by-step explanation:

Consider the provided information.

You have designed an experiment manipulating room temperature (cold, warm, or hot), noise level (quiet or loud), and room color (pink, blue, or black).

The main effect is the influence of an independent variable on an average dependent variable at any other independent variable stage.

Here we have 3 major conditions that are specify in the experiment:

1) Room temperature

2) Noise level

3) Room color

Hence, there are three factor or we can say that 3 main effects.