### 1.1 State the sample size of this investigation.
The sample size refers to the number of subjects within each group being studied. In this investigation, each group (A, B, and C) has 3 rats.
So, the sample size is 3.
### 1.2 Calculate the average mass of (i), (ii) and (iii).
To find the average mass of the rats after a certain period for each group, we will sum the masses of the three rats in the group and then divide by 3.
#### Group A (Diet X)
- Mass of Rat 1: 320g
- Mass of Rat 2: 322g
- Mass of Rat 3: 322g
The average mass [tex]\( (i) \)[/tex] can be calculated as:
[tex]\[ \frac{320 + 322 + 322}{3} = \frac{964}{3} = 321.33 \][/tex]
#### Group B
- Mass of Rat 1: 305g
- Mass of Rat 2: 315g
- Mass of Rat 3: 308g
The average mass [tex]\( (ii) \)[/tex] can be calculated as:
[tex]\[ \frac{305 + 315 + 308}{3} = \frac{928}{3} = 309.33 \][/tex]
#### Group C
- Mass of Rat 1: 345g
- Mass of Rat 2: 338g
- Mass of Rat 3: 337g
The average mass [tex]\( (iii) \)[/tex] can be calculated as:
[tex]\[ \frac{345 + 338 + 337}{3} = \frac{1020}{3} = 340.00 \][/tex]
### 1.3 Which group has the highest average:
Now, let's compare the average masses:
- Average mass for Group A (Diet X): 321.33g
- Average mass for Group B: 309.33g
- Average mass for Group C: 340.00g
The group with the highest average mass is Group C with an average mass of 340.00g.
