About eighty five percent of the population is heterozygous for the dominant grey tail color trait. (Decimal form 0.85)
I took 15,000 divided by 12750
Next I took my answer (1.1764705882352941176470588235294 or 1.17 --> 1.18 (rounded up)) and divided 100 by that number. You would get 85.000000000000000000000000000001 or 85..
85%