Simpsons Variables Worksheet: A fun educational activity using characters from The Simpsons to teach scientific method concepts like independent, dependent, and controlled variables.

Let's solve each section of the Simpsons Variables Worksheet step by step, identifying variables and analyzing the experiments.

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1. Smithers' Juice Experiment

Scenario:
Smithers tests whether a special juice increases worker productivity by giving different amounts to three groups of 50 workers. Each group staples papers for one hour.

- Group 1: 100mL of juice → 1,030 sets stapled
- Group 2: 50mL of juice → 1,700 sets stapled
- Group 3: No juice → 2,113 sets stapled

#### Identify the variables:

1. Independent Variable:
The amount of special juice consumed.
*(This is what Smithers changes: 100mL, 50mL, or 0mL)*

2. Dependent Variable:
The number of sets of paper stapled.
*(This is what is being measured as the outcome)*

3. Controlled Variables:
- Number of workers in each group (50)
- Task assigned (stapling papers)
- Time allowed (1 hour)
- Type of task and materials used
*(These are kept constant to ensure fair comparison)*

4. What should Smithers' conclusion be? How did the juice affect productivity?

Looking at the data:
- Group 3 (no juice): 2,113 sets
- Group 2 (50mL): 1,700 sets
- Group 1 (100mL): 1,030 sets

Conclusion:
The special juice decreased productivity. Workers who drank more juice stapled fewer papers.

- Group 1 (100mL) stapled 1,030, which is less than half of Group 3.
- Group 2 (50mL) stapled 1,700, still significantly less than Group 3.

Therefore, the juice appears to hinder productivity rather than help it.

Answer:
Smithers should conclude that the special juice reduces productivity. The more juice consumed, the fewer papers were stapled. This suggests the juice may have a negative effect on work performance.

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2. Homer’s Shower Slime Experiment

Scenario:
Homer sprays coconut juice on half the shower and water on the other half. After 3 days, no change occurs on either side.

#### Identify the variables:

1. Independent Variable:
The type of liquid sprayed (coconut juice vs. water)

2. Dependent Variable:
The appearance/amount of green slime on the shower

3. Hypothesis (If... then... because):

> If coconut juice is applied to the shower, then it will remove the green slime, because coconut juice has natural cleaning properties.

*(Note: This is a reasonable hypothesis based on Barney’s claim.)*

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3. Krusty’s Itching Powder Experiment

Scenario:
Krusty compares two itching powders:
- Subject A: Original powder → itched for 30 minutes
- Subject B: New experimental powder → itched for 45 minutes

#### Identify the variables:

1. Independent Variable:
Type of itching powder used (original vs. new experimental)

2. Dependent Variable:
Duration of itching (in minutes)

3. What should Krusty’s conclusion be? Use data to support your answer.

- Original powder: 30 minutes
- New powder: 45 minutes

Difference: 45 – 30 = 15 minutes longer

Claim was that the new powder causes 50% longer lasting itches.

Let’s check:
50% of 30 minutes = 15 minutes → 30 + 15 = 45 minutes

✔ So the new powder does cause 50% longer itching.

Conclusion:
The new itching powder produces itches that last 50% longer than the original, as claimed. The data supports the product’s claim.

4. How could Krusty improve his experiment?

- Use more test subjects to get reliable results (only 2 subjects is too small).
- Randomize which subject gets which powder.
- Blind the test — subjects shouldn’t know which powder they’re getting.
- Repeat the experiment multiple times.
- Ensure consistency in how much powder is applied and where.
- Control for individual differences (e.g., skin sensitivity).

These improvements would make the experiment more valid and reliable.

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✔ Final Answers Summary

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#### Smithers’ Experiment
1. Independent Variable: Amount of special juice consumed
2. Dependent Variable: Number of sets of paper stapled
3. Controlled Variables: Number of workers, task, time, materials
4. Conclusion: The juice reduced productivity. Group 3 (no juice) stapled 2,113 sets; Group 1 (100mL) only 1,030 — showing a clear decline with more juice.

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#### Homer’s Experiment
1. Independent Variable: Type of liquid (coconut juice vs. water)
2. Dependent Variable: Appearance of green slime
3. Hypothesis:
*If* coconut juice is sprayed on the shower, *then* it will remove the green slime, *because* it has cleaning properties.

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#### Krusty’s Experiment
1. Independent Variable: Type of itching powder
2. Dependent Variable: Duration of itching (minutes)
3. Conclusion: The new powder caused 45 minutes of itching vs. 30 minutes — a 50% increase. The claim is supported.
4. Improvements: Use more subjects, randomize, blind the test, repeat trials.

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