Final answer:
The cross of a homozygous red-flowered plant (RR) with a pink-flowered plant (RW) would result in offspring with a 1:1 genotypic ratio of red (RR) to pink (RW) flowers, demonstrating incomplete dominance.
Step-by-step explanation:
The scenario described in the student's question revolves around the inheritance pattern of flower color in four-o'clock plants, which is a classic example of incomplete dominance. In this mode of inheritance, a heterozygous individual expresses a phenotype that is a mix of both homozygous parents. Therefore, a pink-flowered plant (RW) is the result of a cross between a red-flowered (RR) and a white-flowered (WW) plant. If we consider a cross between a homozygous red-flowered plant (RR) and a pink-flowered plant (RW), the possible genotypes of the offspring would be either red (RR) or pink (RW), since pink is the expression of the RW genotype.
Using a Punnett Square, we can predict the genotypic ratio of the potential offspring. As for the phenotypes, since the red allele (R) is incompletely dominant over the white allele (W), and because the RW genotype results in pink flowers, half of the offspring are expected to have red flowers (RR) and the other half to have pink flowers (RW).