Sponge Bob Scientific Method Controls and Variables-Part 2 ... - Free Printable

Problem Analysis and Solution

The worksheet involves two experiments related to the scientific method, focusing on controls and variables. Let's solve each part step by step.

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#### Experiment 1: Krusty Krabs Breath Mints

Description:
Mr. Krabs created a secret ingredient for a breath mint that he believes will "cure" bad breath from eating crabby patties. He conducted an experiment with 100 customers divided into two groups:
- Group A (50 people): Received the new breath mint with the secret ingredient.
- Group B (50 people): Received a regular breath mint without the secret ingredient.
Both groups were told they were getting the same breath mint. After eating crabby patties, 30 people in Group A reported better breath, while 10 people in Group B reported better breath.

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##### Questions and Solutions:

1. Which people are in the control group?
- The control group is the group that does not receive the experimental treatment. In this case, Group B is the control group because they received the regular breath mint without the secret ingredient.

2. What is the independent variable?
- The independent variable is the factor that is manipulated by the experimenter. Here, it is the type of breath mint given to the customers:
- Group A: New breath mint with the secret ingredient.
- Group B: Regular breath mint without the secret ingredient.
- Answer: The independent variable is the type of breath mint (with or without the secret ingredient).

3. What is the dependent variable?
- The dependent variable is the outcome being measured, which depends on the independent variable. In this case, it is the reported improvement in breath quality after eating crabby patties.
- Answer: The dependent variable is the reported improvement in breath quality.

4. What should Mr. Krabs’ conclusion be?
- To draw a conclusion, we compare the results of the two groups:
- Group A (new breath mint): 30 out of 50 people reported better breath.
- Group B (regular breath mint): 10 out of 50 people reported better breath.
- The higher number of people reporting better breath in Group A suggests that the secret ingredient may have a positive effect on breath quality.
- Conclusion: Mr. Krabs should conclude that the secret ingredient in the new breath mint likely improves breath quality compared to the regular breath mint.

5. Why do you think 10 people in group B reported fresher breath?
- Even though Group B received the regular breath mint without the secret ingredient, some people still reported better breath. This could be due to several factors:
- Placebo effect: People may feel better simply because they believe the breath mint will work.
- Natural variation: Some people might have had better breath naturally after eating crabby patties.
- Subjective perception: The perception of breath quality can vary from person to person.
- Answer: The 10 people in Group B who reported fresher breath may have experienced the placebo effect, natural variation, or subjective perception.

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#### Experiment 2: SpongeBob Clean Pants

Description:
SpongeBob noticed his pants were dirty and wanted to test if Clean-O detergent would make them cleaner. He washed one pair of pants in plain water and another pair in water with Clean-O detergent. After washing both pairs three times, there was no noticeable difference in cleanliness.

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##### Questions and Solutions:

6. What was the problem SpongeBob wanted to investigate?
- SpongeBob wanted to determine whether using Clean-O detergent would make his pants cleaner than washing them in plain water.
- Answer: The problem SpongeBob wanted to investigate is whether Clean-O detergent makes pants cleaner.

7. What is the independent variable?
- The independent variable is the factor that SpongeBob manipulated. In this case, it is the type of water used for washing:
- One pair of pants: Washed in plain water.
- Another pair of pants: Washed in water with Clean-O detergent.
- Answer: The independent variable is the type of water used for washing (plain water vs. water with Clean-O detergent).

8. What is the dependent variable?
- The dependent variable is the outcome being measured, which depends on the independent variable. Here, it is the cleanliness of the pants after washing.
- Answer: The dependent variable is the cleanliness of the pants.

9. What should SpongeBob’s conclusion be?
- After washing both pairs of pants three times, there was no noticeable difference in cleanliness between the pants washed in plain water and those washed with Clean-O detergent.
- Conclusion: SpongeBob should conclude that Clean-O detergent does not make his pants any cleaner than washing them in plain water.

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Final Answers:

1. Control group: Group B
2. Independent variable: Type of breath mint (with or without the secret ingredient)
3. Dependent variable: Reported improvement in breath quality
4. Mr. Krabs’ conclusion: The secret ingredient in the new breath mint likely improves breath quality.
5. Reason for Group B reporting fresher breath: Placebo effect, natural variation, or subjective perception

6. Problem SpongeBob wanted to investigate: Whether Clean-O detergent makes pants cleaner
7. Independent variable: Type of water used for washing (plain water vs. water with Clean-O detergent)
8. Dependent variable: Cleanliness of the pants
9. SpongeBob’s conclusion: Clean-O detergent does not make pants any cleaner than washing them in plain water.

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Final Boxed Answers:

1. Group B
2. Type of breath mint (with or without the secret ingredient)
3. Reported improvement in breath quality
4. The secret ingredient in the new breath mint likely improves breath quality.
5. Placebo effect, natural variation, or subjective perception

6. Whether Clean-O detergent makes pants cleaner
7. Type of water used for washing (plain water vs. water with Clean-O detergent)
8. Cleanliness of the pants
9. Clean-O detergent does not make pants any cleaner than washing them in plain water.

Final Answer:
\boxed{
\begin{array}{l}
1. \text{Group B} \\
2. \text{Type of breath mint (with or without the secret ingredient)} \\
3. \text{Reported improvement in breath quality} \\
4. \text{The secret ingredient in the new breath mint likely improves breath quality.} \\
5. \text{Placebo effect, natural variation, or subjective perception} \\
6. \text{Whether Clean-O detergent makes pants cleaner} \\
7. \text{Type of water used for washing (plain water vs. water with Clean-O detergent)} \\
8. \text{Cleanliness of the pants} \\
9. \text{Clean-O detergent does not make pants any cleaner than washing them in plain water.}
\end{array}
}