Suppose in humans an autosomal gene, a, causes dwarfism in one homozygous state (a'a), normal height in the heterozygous state (a'a), and is embryonic lethal in the other homozygous state (aa). A separate gene, p, found on another chromsoome causes albinism, an autosomal recessive disorder. Albino individuals have the pp genotype. Rick and Lori, who are both heterozygous for both genes (a'a p'p), just had a son, Carl. What is the probability that Carl is of normal height with albinism?