Analyzing Data | PDF - Free Printable

Let's go through both problems step by step and analyze the data carefully.

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1. Mouse Experiment

Objective: Determine whether an experimental drug affects the number of offspring in female mice.

#### Data:
- Group A (Drug): 5, 6, 4, 8, 5, 2, 7, 12, 12, 8
- Group B (Control): 4, 4, 6, 6, 5, 6, 4, 7, 5, 3

We are told that:
- Group A received the drug.
- Group B did not (control group).

We need to compare the total number of babies in each group.

#### Step 1: Calculate Total Number of Babies
- Group A (Drug):
5 + 6 + 4 + 8 + 5 + 2 + 7 + 12 + 12 + 8 = 69

- Group B (Control):
4 + 4 + 6 + 6 + 5 + 6 + 4 + 7 + 5 + 3 = 50

So, the drug group had 69 babies, and the control group had 50 babies.

#### Conclusion:
The drug appears to have increased the average litter size.

But let’s be more precise. Let's calculate the average (mean) per litter:

- Group A (Drug): 69 ÷ 10 = 6.9 babies per litter
- Group B (Control): 50 ÷ 10 = 5.0 babies per litter

This shows a significant increase in litter size in the drug group.

Additionally, note that the drug group has two litters of 12, which are unusually high, while the control group has more consistent but smaller litters.

#### ✔ Final Answer:
> Yes, the drug appears to work because the experimental group had a significantly higher total number of offspring (69 vs. 50) and a higher average litter size (6.9 vs. 5.0). This suggests the drug may enhance fertility or litter size in mice.

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2. Cow Growth Rates

Objective: Compare growth rates of two twin cows — one on experimental feed (Bessie), one on regular corn feed (Bertha).

#### Data Table:

| Month | April | May | June | July | Aug |
|-------|-------|-----|------|------|-----|
| Bessie | 100 lbs | 210 lbs | 260 lbs | 320 lbs | 400 lbs |
| Bertha | 100 lbs | 250 lbs | 290 lbs | 340 lbs | 400 lbs |

#### Graph Instructions:
- Use dotted line for Bessie
- Use straight line for Bertha
- Label X-axis: Months (A, M, JN, JL, AU)
- Label Y-axis: Weight (lbs)

Let’s plot the points:

- Bessie (Dotted Line):
- April: (A, 100)
- May: (M, 210)
- June: (JN, 260)
- July: (JL, 320)
- August: (AU, 400)

- Bertha (Straight Line):
- April: (A, 100)
- May: (M, 250)
- June: (JN, 290)
- July: (JL, 340)
- August: (AU, 400)

Now, even though both end at 400 lbs, their growth patterns differ.

#### Analysis of Growth Patterns:

- Bessie (Experimental Feed):
- Grew slowly from April to May: 100 → 210 (+110 lbs)
- Then gradually increased: 210 → 260 (+50), 260 → 320 (+60), 320 → 400 (+80)
- Overall: Slow start, then faster growth later

- Bertha (Regular Feed):
- Grew fast in May: 100 → 250 (+150 lbs)
- Then slower: 250 → 290 (+40), 290 → 340 (+50), 340 → 400 (+60)
- Overall: Fast initial gain, then slower steady growth

#### Did the experimental feed change how they gained weight?
Yes. The rate of weight gain was different over time:
- Bessie started slow and accelerated later.
- Bertha started strong and slowed down.

Even though they ended at the same weight, the pattern of growth differs.

#### Why is it important that the experiment used twin cows?
Using twin cows ensures that:
- They are genetically identical (same DNA),
- Likely similar in health, metabolism, and starting conditions,
- Reduces variables like genetics, age, or initial health.

This makes the comparison fairer — any differences in growth can be more confidently attributed to the type of feed rather than other factors.

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✔ Final Answer for Cow Experiment:

> Yes, the experimental feed changed the way the cows gained weight. While both cows reached the same final weight (400 lbs), Bessie (experimental feed) gained weight more slowly at first and accelerated later, while Bertha (regular feed) had a rapid early gain followed by slower growth. This shows the feed affected the growth pattern, not just the final outcome. Using twin cows is crucial because it controls for genetic and developmental differences, making the results more reliable and directly attributable to the feed.

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Summary of Answers:

1. Mouse Experiment:
→ The drug worked because the experimental group had more offspring (69 vs. 50), indicating increased fertility.

2. Cow Growth Rates:
→ The experimental feed changed the growth pattern (slower start, faster finish), even though final weights were equal.
→ Twin cows were used to minimize genetic variability, ensuring a fair test.

Let me know if you'd like a labeled graph drawn out!