Hemoglobin ( Hb ) protein transport O 2 in blood and each Hb can bind 4 O 2 , molecules. In discussing…

Hemoglobin $\left(\mathrm{Hb}\right)$ protein transport ${\mathrm{O}}_2$ in blood and each $\mathrm{Hb}$ can bind $4{\mathrm{O}}_2$, molecules. In discussing protein oxygen binding capacity, biochemists use a measure called the ${\mathrm{P}}^{50}$ value, defined as the partial pressure of oxygen at which $50\%$ of hemoglobin is saturated. Fetal hemoglobin has a ${\mathrm{P}}^{50}$ value of $20$ torr and adult has ${\mathrm{P}}^{50}$ value of $40$ torr. For the following equilibrium:

$4{\mathrm{O}}_2( \mathrm{g})+\mathrm{Hb}\left(\mathrm{aq}\right)\to \left[\mathrm{Hb}{\left({\mathrm{O}}_2\right)}_4\left(\mathrm{aq}\right)\right]$

What is the value of ${\mathrm{K}}_{\mathrm{fetal}}/{\mathrm{K}}_{\mathrm{adult}}?$

[Where $\mathrm{K}$ represents equilibrium constant.]