The Simpsons-themed science worksheet teaches students about experimental design through fun scenarios involving characters like Smithers, Homer, Bart, Krusty, and Lisa, with questions on identifying variables and improving experiments.

Let's solve each of the problems step by step based on the scenarios provided in the image. Each scenario is a classic example of a scientific experiment, and we need to identify the control group, independent variable, dependent variable, draw conclusions, and suggest improvements.

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Scenario 1: Smithers and the Special Juice

Situation:
Smithers tests whether a special juice increases worker productivity. He has two groups of 50 workers:
- Group A: Given the special juice
- Group B: Not given the juice
Both groups do the same task (stacking papers). After one hour:
- Group A made 1,587 stacks
- Group B made 2,113 stacks

#### 1. Control Group
✔ Group B – This group does not receive the special juice and serves as the baseline for comparison.

#### 2. Independent Variable
✔ Whether or not the workers received the special juice – This is what Smithers is changing.

#### 3. Dependent Variable
✔ Number of paper stacks made – This is what is being measured to see the effect of the juice.

#### 4. What should Smithers’ conclusion be?
✘ The special juice did not increase productivity — in fact, Group B (no juice) performed better than Group A (with juice).
So, Smithers should conclude that the special juice does not improve productivity and may even have a negative effect.

#### 5. How could this experiment be improved?
✔ Random assignment of workers to groups to avoid bias.
✔ Double-blind setup (if possible): Workers and observers don’t know who got the juice.
✔ Larger sample size or repeated trials.
✔ Ensure both groups are equally motivated and working under the same conditions.
✔ Test multiple days to confirm results.

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Scenario 2: Homer and the Green Slime

Situation:
Homer notices green slime on his shower. Barney suggests coconut juice might remove it. Homer sprays half the shower with coconut juice and the other half with water. After 3 days, no change in either side.

#### 6. What was the initial observation?
✔ Homer noticed that his shower was covered in a strange green slime.

#### 7. Control Group
✔ The half of the shower sprayed with water – this is the baseline to compare against the treatment.

#### 8. Independent Variable
✔ Type of liquid used – coconut juice vs. water.

#### 9. Dependent Variable
✔ Appearance of the green slime – whether it changed or disappeared.

#### 10. What should Homer’s conclusion be?
✔ Coconut juice does not remove the green slime, since there was no difference between the treated and untreated sides.

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Scenario 3: Bart and Microwaves & Mice

Situation:
Bart believes mice exposed to microwaves become stronger. He exposes 10 mice to microwaves for 10 seconds and compares them to 10 non-exposed mice. Both groups are tested on pushing a heavy block. Results:
- Microwave group: 3 out of 10 succeeded
- Non-microwave group: 7 out of 10 succeeded

#### 11. Control Group
✔ The non-microwave group – these mice were not exposed to microwaves and serve as the control.

#### 12. Independent Variable
✔ Exposure to microwave radiation – yes or no.

#### 13. Dependent Variable
✔ Ability to push the block – success or failure.

#### 14. What should Bart’s conclusion be?
✔ The data shows that microwave exposure did not make mice stronger; in fact, the non-exposed mice performed better.
So, Bart should conclude that microwaves do not increase mouse strength.

#### 15. How could Bart’s experiment be improved?
✔ Use more mice to reduce chance variation.
✔ Randomly assign mice to groups.
✔ Ensure all mice are the same age, size, and health.
✔ Repeat the test multiple times.
✔ Control for environmental factors (temperature, time of day).
✔ Blind testing (observer doesn't know which group is which).

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Scenario 4: Krusty and Itching Powder

Situation:
Krusty tests an itching powder claimed to cause "30% longer lasting itches." He uses:
- Subject A: Original product → itches for 30 minutes
- Subject B: Experimental product → itches for 45 minutes

#### 16. Control Group
✔ Subject A – who used the original product (standard condition).

#### 17. Independent Variable
✔ Type of itching powder – original vs. experimental.

#### 18. Dependent Variable
✔ Duration of itching – how long the itch lasts.

#### 19. Explain whether the data supports the advertisement’s claim about its product.
✔ Yes, the data supports the claim.
- Original: 30 minutes
- Experimental: 45 minutes
→ That’s a 50% increase, which is more than the advertised 30%.
So, the experimental powder does cause longer-lasting itches, and actually exceeds the claim.

⚠️ However, the sample size is extremely small (only 2 subjects), so while the result is promising, it’s not statistically reliable. More testing would be needed.

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Scenario 5: Lisa and Rogooti Hair Growth

Situation:
Lisa wants to test if Rogooti (a hair product) affects the speed of hair growth. Her family volunteers.

#### 20. Describe how Lisa would perform this experiment. Identify the control group and independent and dependent variables.

✔ Experiment Design:
- Lisa will select several family members.
- She divides them into two groups:
- Control Group: Family members who do not use Rogooti (use regular shampoo or nothing).
- Experimental Group: Family members who apply Rogooti regularly (e.g., daily).
- All participants must follow the same hair care routine otherwise (same brushing, washing frequency, diet, etc.).
- Hair length is measured at the start and after a fixed period (e.g., 4 weeks).
- Lisa records the amount of hair growth for each person.

✔ Control Group: The group not using Rogooti.

✔ Independent Variable: Use of Rogooti (yes/no).

✔ Dependent Variable: Rate of hair growth (measured in cm per week or similar).

✔ Improvements:
- Random assignment of family members to groups.
- Blind testing (participants don’t know who gets Rogooti).
- Long-term study (multiple months).
- Measure hair growth from the same spot on the head.
- Include multiple participants to get reliable data.

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✔ Final Summary Table:

| Question | Answer |
|--------|--------|
| 1. Control Group (Smithers) | Group B |
| 2. Independent Variable (Smithers) | Special juice |
| 3. Dependent Variable (Smithers) | Number of paper stacks |
| 4. Conclusion (Smithers) | Special juice did not increase productivity |
| 5. Improvement (Smithers) | Random assignment, larger sample, blind testing |
| 6. Initial Observation (Homer) | Green slime on shower |
| 7. Control Group (Homer) | Water-sprayed side |
| 8. Independent Variable (Homer) | Type of liquid (coconut juice vs. water) |
| 9. Dependent Variable (Homer) | Appearance of slime |
| 10. Conclusion (Homer) | Coconut juice does not remove slime |
| 11. Control Group (Bart) | Non-microwave mice |
| 12. Independent Variable (Bart) | Microwave exposure |
| 13. Dependent Variable (Bart) | Ability to push block |
| 14. Conclusion (Bart) | Microwaves do not make mice stronger |
| 15. Improvement (Bart) | Larger sample, randomization, controls |
| 16. Control Group (Krusty) | Subject A (original powder) |
| 17. Independent Variable (Krusty) | Type of itching powder |
| 18. Dependent Variable (Krusty) | Duration of itching |
| 19. Supports ad claim? | Yes, but only with small sample |
| 20. Lisa’s Experiment | Control: no Rogooti; IV: Rogooti use; DV: hair growth rate |

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This completes the analysis of all five scenarios! Let me know if you'd like a printable version or a diagram.