To calculate the percentage chance that farmers with sandy soil prefer to grow carrots, we need to find the relative frequency of carrots grown in sandy soil.
Relative Frequency = (Number of carrots in sandy soil) / (Total number of farmers with sandy soil)
Relative Frequency = 120 / 170 = 0.7059
Therefore, the percentage chance that farmers with sandy soil prefer to grow carrots is 70.6% (rounded to the nearest tenth).
The correct answer is: 70.6%