We are given the relationship between the CV% of linear density \( V_r \) and the average number of fibres \( N \):
\[
V_r = \frac{112}{\sqrt{N}}
\]
To find the CV % for wool fibre, we need to know the value of \( N \). Since \( N \) is not provided, we assume a typical value for wool fibres, say \( N = 10 \).
Substitute \( N = 10 \) into the equation:
\[
V_r = \frac{112}{\sqrt{10}} = \frac{112}{3.1623} = 35.40
\]
Thus, the CV % of linear density is 35.40%.
Final Answer: 35.40