Sure, here is the detailed, step-by-step solution to the given questions:
### 1.1 State the sample size of this investigation.
The sample size for this investigation is [tex]\(12\)[/tex].
Answer: 12
---
### 1.2 Calculate the average mass of (ii) and (iii).
To find the average mass of rats in group B:
- For part (ii), the mass of the rats is given as:
[tex]\[
\text{masses} = 320 \, \text{g} \quad \text{and} \quad 318 \, \text{g}
\][/tex]
The average mass of (ii) is:
[tex]\[
\frac{320 + 318}{2} = 319 \, \text{g}
\][/tex]
- For part (iii), the mass of the rats is given as:
[tex]\[
\text{masses} = 345 \, \text{g}, \quad 338 \, \text{g}, \quad \text{and} \quad 337 \, \text{g}
\][/tex]
The average mass of (iii) is:
[tex]\[
\frac{345 + 338 + 337}{3} = 340 \, \text{g}
\][/tex]
- Combining the average masses of (ii) and (iii):
[tex]\[
\text{Average mass} = \frac{319 + 340}{2} = 329.5 \, \text{g}
\][/tex]
Answer: 329.5 g
---
### 1.3 Which group has the highest average:
a) Oxygen consumption
The highest average oxygen consumption is not provided in the given information.
Answer: Not specified
b) Average mass after three weeks
From the data:
- Rat masses averaged in Group A: [tex]\(\frac{320 + 321}{2} = 320.5\)[/tex]
- Rat masses averaged in Group B (ii): 319 g
- Rat masses averaged in Group B (iii): 340 g
The highest average mass among these groups after three weeks is:
[tex]\[
\text{Highest average mass} = 340 \, \text{g}
\][/tex]
Answer: 340 g
---
### 1.4 What effect does an increase in thyroxin have on oxygen consumption?
The effect of an increase in thyroxin on oxygen consumption is not provided in the given information.
Answer: Not specified
---
### 1.5 Which group (A, B, or C) is the control in this investigation?
The control group in this investigation is:
Answer: C
---
### 1.6 Identify the diet (X, Y, or Z) used for:
a) Group B
The diet used for Group B is not specified.
Answer: Not specified
b) Group C
The diet used for Group C is not specified.
Answer: Not specified
