Answer:
Duplicate dominant epistasis
Explanation:
The cross of two doubly heterozygous individuals is a dihybrid cross AaBb x AaBb. From Mendel's law of independent assortment we expect the following phenotypic ratios in the offspring:
The cross of doubly heterozygous Dontdrinkmycola flowers produced 471 offspring with mauve colored petals, and 29 teal-colored petals (total: 500).
The ratios are:
471/500 ≅ 15/16
29/500 ≅ 1/16
So the ratios are 15:1 and the most likely form of epistasis is duplicate dominant epistasis, where a single copy of a dominant allele of either gene is enough to produce the dominant phenotype (mauve colored petals).