To find the percentage chance that farmers with sandy soil prefer to grow carrots, we need to use the relative frequency formula. The formula for relative frequency is:
\[ \text{Relative Frequency} = \frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes for the group}} \]
In this case:
- The number of farmers with sandy soil who prefer to grow carrots is 120.
- The total number of farmers with sandy soil is 170.
Now we can calculate the relative frequency:
\[ \text{Relative Frequency} = \frac{120}{170} \]
Calculating this gives:
\[ \text{Relative Frequency} \approx 0.70588235294 \]
To convert this into a percentage, multiply by 100:
\[ 0.70588235294 \times 100 \approx 70.5882352941 \]
Rounding this to the nearest tenth, we get 70.6%.
Thus, the answer is 70.6%.