Question

your turn: for each item below, identify the independent and dependent variables, (a) not all 1 a study was done to find if different tire brands affect the braking distance of a car a. iv b. dv c. cv 2 the time it takes to run a mile depends on the person’s running speed a. iv b. dv c. cv 3 the height of bean plants depends on the amount of water they receive a. iv b. dv c. cv 4 the higher the temperature of the air in the oven, the faster a cake will bake. a. iv b. dv c. cv 5 lemon trees receiving the most water produced the most lemons. a. iv b. dv c. cv 6 an investigation found that more bushels of potatoes were produced when the soil was fertilized more. a. iv: b. dv: c. cv: 7 students measured the temperature of the water at different depths in lake skywalker and found that the temperature varied. a. iv: b. dv: c. cv: 8 fish eggs: a scientist knows that the percent of fish eggs that hatch is affected by the temperature of the water in the aquarium. she is attempting to identify which water temperature will cause the highest percentage of fish eggs to hatch. the scientist sets up 5 aquariums at the following temperatures: 10°c, 20°c, 30°c, 40°c, and 50°c. she adds 50 fish eggs to each aquarium and records the number of eggs that hatch in each aquarium. a. iv: b. dv: c. list 3 variables that should be controlled (held constant):

Explanation:

Question 1

To determine the variables:

• Independent Variable (IV): The variable that is manipulated or changed. Here, the "different tire brands" are what's being changed to see its effect.
• Dependent Variable (DV): The variable that is measured or affected. The "braking distance of a car" is what's being measured as a result of changing tire brands.
• Controlled Variable (CV): Variables kept constant. But for part a (IV), it's the tire brand; part b (DV) is braking distance; part c (CV) would be things like car model, speed before braking, road conditions (kept constant).

• IV: The variable causing change. "Person’s running speed" is what's changed (or varies) to affect the time.
• DV: The variable affected. "Time to run a mile" is what's measured as it depends on speed.
• CV: Variables kept constant, like the distance of the mile (always 1 mile), running path (same path), weather conditions (kept same).

• IV: The manipulated variable. "Amount of water" is what's changed to see its effect on bean plants.
• DV: The measured variable. "Height of bean plants" is what's measured as it depends on water.
• CV: Variables kept constant, like type of bean plant, soil type, light exposure (kept same).

Answer:

a. IV: tire brand
b. DV: braking distance of a car
c. CV: e.g., car model, speed before braking, road surface

Question 2