In an isolated population of the woodland beetle Carabus violaceus, shell texture is controlled by a single gene. The allele for a ridged shell, RRR, is dominant over the allele for a smooth shell, rrr.
A survey of this population shows that 19%19\%19% of the beetles have ridged shells.
Assuming the population is in Hardy–Weinberg equilibrium, calculate the percentage of beetles in this population that are heterozygous for this gene.
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