Question

question 9
key question directions: choose 2 scenarios. read and identify the independent & dependent variable, experimental & control group.

scenario | independent variable | dependent variable | experimental group | control group
--- | --- | --- | --- | ---
a company wants to test a new dog food that is supposed to help overweight dogs lose weight. 50 dogs are chosen to get the new food, and 50 more continue their normal diets. after one month, the dogs are checked to see if they lost any weight. | (filled: new dog food) | (filled: dog’s weight) | (filled: 50 dogs new food) | (filled: 50 dogs normal diet)
a new sunscreen has been developed that is supposed to be more effective at preventing sunburn. 30 participants spray one arm with the new formula, and spray the other arm with the leading formula. after 4 hours in the sun, their skin is evaluated for any redness. | (blank) | (blank) | (blank) | (blank)
a student wants to study the effect of sunlight on plant growth. in his experiment, 12 plants receive normal amounts of sunlight, but half of them are kept under bright sun lamps all night long. after 6 weeks, the plants’ heights are measured. | (blank) | (blank) | (blank) | (blank)

question 10
critical thinking lisa is working on a science project. her task is to answer the question: \does rogooti (which is a commercial hair product) affect the speed of hair growth\. her uncle is willing to volunteer for the experiment.

directions: describe how lisa could conduct her experiment to answer the question.

(image of a person’s head with hair, text as above)

Explanation:

Question 9 (Taking the second scenario: New Sunscreen)

Step1: Identify Independent Variable

The factor being manipulated is the type of sunscreen (new formula vs leading formula), so the independent variable is the new sunscreen formula.

Step2: Identify Dependent Variable

The outcome being measured is skin redness (sunburn), so this is the dependent variable.

Step3: Identify Experimental Group

The group exposed to the new condition (new sunscreen) is the arms sprayed with the new formula.

Step4: Identify Control Group

The group used for comparison (standard/leading sunscreen) is the arms sprayed with the leading formula.

Question 10

Step1: Experimental Design Setup

By dividing the hair into two groups (experimental and control), we can isolate the effect of Rogooti. The key is to keep other variables constant to ensure that any difference in hair growth is due to Rogooti.

Step2: Application of Variables

Applying Rogooti to one group (independent variable manipulation) and a placebo to the other (control) allows for a fair comparison. Controlling other factors (like diet, sleep) is important because they are confounding variables that could also affect hair growth.

Step3: Measurement

Regular measurement of hair length (dependent variable) provides data on how much the hair has grown. Using a consistent measurement method (like a ruler) ensures accuracy.

Step4: Comparison

Comparing the growth in the two groups helps determine if Rogooti has an effect. If the experimental group (with Rogooti) has significantly more growth, we can conclude that Rogooti affects hair growth speed.

Answer:

Scenario	Independent Variable	Dependent Variable	Experimental Group	Control Group