Identifying Dependent and Independent Variables

In an experiment where the amount of sunlight affects the growth rate of a plant, what is the dependent variable?

• Amount of sunlight

• Growth rate of the plant

Which variable is independent: The amount of water given to a plant or the height of the plant?

• The amount of water given to a plant

• The height of the plant

In a study where the number of hours of sleep affects cognitive performance, which is the independent variable?

• Number of hours of sleep

• Cognitive performance

If the amount of sugar added affects the sweetness of a cake, what is the independent variable?

• Amount of sugar added

• Sweetness of the cake

If the temperature affects the rate of ice melting, what is the independent variable?

• Temperature

• Rate of ice melting

Which of the following best describes a dependent variable?

• A variable that changes in response to another variable

• B variable that remains constant

• C variable that determines the outcome of an experiment

• D variable that is manipulated by the researcher

Brad sets up an experiment to see how the mass of a ball affects the distance it rolls off a ramp.  Identify the independent variable.

• distance traveled by the ball

• mass of the ball

• height of the ramp

Sarah is bringing treats to her elementary school class on her birthday. The number of treats she brings in is based on the number of students in her class. t = the number of treats s = the number of students Which of the variables is independent?

• s

• t

Carey and Justin are raising money to purchase books for their school's library. The more money they raise, the more books they will be able to purchase for the library. m = the amount of money Carey and Justin raise b = the number of books Carey and Justin will be able to purchase Which of the variables is dependent?

• m

• b

In order to earn extra money on the weekends, Josie's string quartet performs at wedding receptions. The longer the reception, the more money they earn.
r = the length of the reception
m = the amount of money Josie's quartet earns
Which of the variables is independent?

• r

• m