A scientist is studying insect wing length. An individual from a pure- breeding parental line (P1), for which the VP is 40 mm2, is mated with an individual from a pure- breeding parental line (P2), for which the VP is 80 mm2. This results in F1 progeny that have a VP of 54 mm2. A cross between two F1 progeny results in offspring with a VP of 92 mm. What is the genotypic variance?