Q5.6. In a population, if the proportion of individuals who have sickle-cell disease is 0.40 , and the population is assumed to be at Hardy-Weinberg equilibrium, what is the expected frequency of the HbS allele? (Hint: What is the genotype of people with sickle-cell disease, and how is that genotype represented in the Hardy-Weinberg equation?) \begin{tabular}{l|l|l|l} 0.80 & 0.63 & 0.20 & 0.16 \end{tabular}.