In a population, the frequency of the dominant allele is 0.4

In a population, the frequency of the dominant allele is 0.4. In the next generation, the observed frequencies of the genotypes are as follows: homozygous dominant = 0.64, heterozygous = 0.32, and homozygous recessive = 0.04. What are the expected genotype frequencies? Is the population in Hardy-Weinberg equilibrium? Give a possible explanation for the observed frequencies.