A population of Hawaiian Drosophilia is segregating two alleles, p1 and p2, of the phosphoglucose isomerase (PGI) gene. In a sample of 500 flies from this population, 26% were p1p1 homozygotes, 62% were p1p2 heterozygotes, and 12% were p2p2 homozygotes. Answer the following questions based on this data:

a- What are the frequencies of the p1 and p2 alleles?

b- Are the genotypes in this sample in Hardy-Weinberg Equilibrium?