In an experiment, Jackson tested to see how the size of rocks affects the amount of dirt that washes away when
water flows downhill. Which variable is the independent
variable?
Two students wanted to find out which of their toy race
cars would go the farthest down a ramp. Which of these
should be held constant if they want a fair test of their
cars?
You design an experiment to test the effect of
temperature on bacterial growth. You use three bacteria.
cultures under three heat lamps at different
temperatures. What is the dependent variable in this
experiment?
A student plans to conduct an experiment to determine
how a change in the pH of water affects the population
growth rate of algae. To ensure that her experimental
Jata are valid, she should