To find the conditional relative frequency of students walking to school, given that they live more than a mile away, we need to use the data for students who live 1+ miles away.
From the table:
- The number of students who live 1+ miles away and walk to school is 6.
- The total number of students who live 1+ miles away is 58.
The formula for conditional relative frequency is:
\[ \text{Conditional Relative Frequency} = \frac{\text{Number of students in the category}}{\text{Total in the condition group}} \]
Plugging in the values:
\[ \text{Conditional Relative Frequency} = \frac{6}{58} \approx 0.1034 \]
To express this as a percentage:
\[ 0.1034 \times 100 \approx 10.34% \]
Rounding to the nearest whole number, the conditional relative frequency is approximately 10%.
Thus, the answer is D: 10%.