To calculate the percentage chance that farmers with rocky soil prefer growing peppers, we need to find the relative frequency of peppers among farmers with rocky soil.
Relative frequency of peppers among farmers with rocky soil = Number of farmers with rocky soil growing peppers / Total number of farmers with rocky soil
Relative frequency of peppers among farmers with rocky soil = 150 / 250 = 0.6
Convert 0.6 to a percentage by multiplying by 100:
0.6 * 100 = 60%
Therefore, the percentage chance that farmers with rocky soil prefer growing peppers is 60%.
So the answer is:
60.0%