Question

select the correct answer.

hans is performing an experiment examining how salt affects the speed at which water freezes. he fills four equally sized containers with the same amounts of water. then, in three of the containers, he stirs in varying amounts of salt. the fourth container remains plain water.

hans places all four of the containers in the same freezer and checks the containers every five minutes, recording when the water in each container freezes solid.

in this situation, what do hanss time measurements represent?

the response variable
the control group
the response group
the explanatory variable

Explanation:

Identify the variables in the experimental design

The explanatory variable (independent variable) is the amount of salt added to the water, which is manipulated by the experimenter. The response variable (dependent variable) is the outcome being measured to see how it responds to changes in the explanatory variable.

Analyze the role of the time measurements

The time measurements record how long it takes for the water in each container to freeze solid. This is the outcome variable measured to evaluate the effect of the salt. Therefore, the time measurements represent the response variable.

Answer:

• the response variable (Correct answer)
• the control group
• the response group
• the explanatory variable